When checking for noise, take the valve cover off and then put each cylinder on top dead center and check the intake and exhaust rockers for play. this is the easiest way to find out if you have a worn lifter, bent push rod or worn rockers. If everything checks out, pull the oil pan and check for broken piston parts.
Hi Eric, Thank you for the video, apart from the views of the inept commenters, this is definitely a collapsed hydraulic lifter issue. It is a common misconception that a heavier motor oil will assist the hydraulic lifters to "pump up" so to speak, for example 20w50. I have solved lifter issues by running a lighter oil such as 5w30 and have physically heard the point at which the lifter has quieted down, it is always important to run the oil that the manufacturer specifies, don't just say oh wow the Valvoline Racing 50 is on special today when your engine requires 10w30 of course if the lifter has been collapsed for a period of time then it will be damaged and require replacement, 25 years in the automotive repair industry has taught me to replace the oil first that is your cheapest option and then run the car at cruising speed for 50 miles or so, if the problem persists then it is money spending time. I think that its great that you put yourself out there for public scrutiny so that we might all learn something together. Thanks Eric
have the same noise i have rolled rod bearning in and after idling 20mins the knocking sounds is back.so i used my long screw driver and found the location of the racket comming from the area of the last 2 cylinders under the value cover,any good videos you can suggest on how to aproch this ofcourse im gonna pull the value cover this morninr...
Just wanted to share an experience I had with an '88 Jeep Cherokee that was making very similar engine noise to the one in your vid. After watching several similar vids on youtube I was pretty much convinced the problem was piston slap or the like and was about ready to junk it when I stumbled on the actual culprit. Turned out to be the power steering pump. Pump had been losing fluid and apparently gotten low enough to do serious damage. Apparently, the idler pulley also sustained some collateral damage as well - the bearings were seizing up - some actually torn up and jammed. I replace the steering pump and reservoir and the idler pulley and the horrible noises disappeared immediately. Running like new now - or as close to new as a 4.0 liter with 248k miles can run. I think this shows how difficult diagnosing engine noises can be. I would have bet anything that mine was related to engine internals.
This is definitely not a power steering pump. It is most likely the pistons slapping around due to rings being gone. Check compression and that will be a determining factor if you have a bad rod bearing or worn ring. I think it's a bad rod bearing in that case the motor needs to be rebuilt
Mine sounded just like that and it was a loose torque converter bolt hitting the block. Tightened it and others up and it went away. At first I thought it was a rod knocking because it sounded like it was coming from the lower rear of the engine but then I read somewhere to check the torque converter bolts.
@@firingallcylinders2949 I literally just picked up a 99 WJ 4x4 just now and it was (what I think/thought) tapping the top of the valve cover but sheesh now I want to check this out with the tq bolts everyone is talking about. First jeep, $500, drove me home tapping everywhere 20 miles home lol.
Had that noise in mine around 275,000 mi. I lavished it with over the counter oil additives and cleaners of every sort. Around 250 mi later the noise was gone. Not saying anybody should try this but it was the best choice for me at the time. I've really pounded my Jeep 4.0 High Output. Towed massive loads regularly. Blew the small radiator and switched to bigger. When you overheat go ahead and replace water pump. Due to oil leaks I've run it very low on oil several times. This engine gained my respect and I now baby it. It is at 400,000 mi now and the only work on it was replaced timing chain. That's one timing chain in 400,000 mi...amazing. Knock on wood. The oil leak probably helped keep the oil clean. It's fun to think do I want to rebuild and make everything perfect, or wait and see how long it will last. I know several people who dislike the engine. As far as I'm conserned it's bullet proof...knock on wood.
Actually, these engines are amazingly well engineered and built. This is why they had such a long run with AMC, then when Chrysler bought the Jeep brand, continued to produce them with minor modifications.
I saw the comment about the head weeping antifreeze between the #5 and 6 cylinder. This was corrected in 2003 with the TUPY 331 head. I have an '04 JGC with the 4.0 inline 6 with 230k miles on it The timing chain is still quite as the day it was new. No oil use whatsoever...but I have maintained this vehicle better than the dealer manual suggests. A big plus is flushing your antifreeze every 30k and also use nothing but Royal Purple 10W-30. So at 230k, she is still in her teenage years.
The change was actually made in 2002, the original 0331 heads have a tendency to crack between #5 and 6. The head that replaced it is identical except for the area that cracked being modified (thicker if I remember right) and a TUPY forge mark visible on that spot as well.
Dude the reason the paper clips got stuck is because that's a ball and socket and when you stick the paper clip down in there that feed hole moves back and forth go out and get you some rocker arm shields that you just clip right to the rocker rocker arm and it diverts the oil snap on Mac or Matco safest way to go never stick anything down a pushrod hole you're just asking for trouble
izzynutz2000 you are correct, that is prob why the engine blew after he worked on it....Id never let him work on my jeep after seeing that, its was kinda of funny when he said, on they get a little stuck, Blahhhh ha
even a pos shitty jeep with a 4.0 i6 will last longer and go further than any other car out there, rain snow sand mud or flood, a jeep will get you there, at least a real jeep not this new fiat bullshit, and you will have more fun doing it. and don't forget that the jeep along with harley davidson helped america win wars, so to say fuck jeeps, is like saying fuck america, and fuck freedom, so you can take your nazi bullshit to fuckkity off land and take your little bitchmobile with you
I have a 98 Jeep GC with a 4.0L engine. I bought it new. Did all the maintenance myself. Only used Amsoil lubricants. So far I had no issues with the engine or anything else. I did a lot of towing and off-roading with it. Great reliable vehicle. I've owned a lot of Hondas and Toyotas, The Jeep has been a lot more reliable and very capable vehicle. Can't say this about my 2010 Tacoma. Hondas were the worst POS.
Andrew Ivanov Well, you were the exemption to the rule, because statistics show otherwise: Hondas and Toyotas are the most reliable vehicles and the most cheap to maintain.
I count about 8 "ticks" per second, or 480 a minute; assuming it's idling at just under 1000 rpm cold, that means the ticking frequency is 1/2 the engine RPM. Wouldn't that indicate a valvetrain issue? I'd expect a piston problem to sound with a frequency matching the RPMs.
Piston only fires every 4 strokes. Its possible it coincides with "firing" event, but that's a great assessment and very possible it's just Valvetrain.
also for those having a knocking in the engine. on some models there's a knock sensor that will eventually fail. causing the low end knock. there's also camshaft position sensor and crankshaft position sensor. if,any of these are bad, a knock will occur.
I tell everyone to do their oil changes every 3k. It could have saved that engine probably. Lack of maintenance kills me. Its like throwing 5k in the trash. Cause now they going to need another vehicle.
I'm surprised he didn't even go under the car. I have a sound just like this on my xj 4.0 and at first thought it was the motor. Went under the engine and it was coming from the bell housing. It's pretty common for the flex plate bolts to come loose, and the flex plate can crack as well.
These 4.0s are notorious for cracked piston skirts. That was a pretty loud "tap" and I would be willing to bet it was piston slap rather than a lifter.
Joey Quigley you are correct. Also, when the noise is just like in the video, it is in fact a piston. I know from experience, drove almost a year with this tick and finally the piston skirt blew. It was ultimately caused from non existent oil changes from the previous owner. Ended up getting a new engine.
Joey Quigley Ugh, sucks. On the bright side, after I blew the piston it got me home and then to my buddies/mechanics house...about 40 miles... loud as hell lol. And, we started it up again and ripped it a few times down the road. Tough ass engine. PLEASE CHANGE YOUR OIL PEOPLE!!!
Same here. Ran fine for about a year then - one loud bang and the motor cut out. I restarted her and drove home, about 15 miles - trailing lots of smoke and oil. On inspection, found that the #2 piston was gone, totally disintegrated and the rod had cut groove into the cylinder wall. The remains of the piston had knocked a large hole in the sump cover. Tough ass engine as you say, but better have it checked out before you blow that piston.
Yeah about 5 years late on this one but I was thinking the same thing whenever he called it a “heat shield” and only a heat shield because that’s when most backyard guys will say blah don’t need this anymore....lol but you do it’s to prevent the injectors from becoming heat soaked and causing further problems we don’t wanna fix one problem to create 2 more
This is what happened to my jeep. Thanks Eric. I left it parked on the side of the road. It had that knock and I saw a puff of white smoke from engine bay and it didn't blow a rod or anything just seized up. Wont even turn over.
Thanks Eric! I always enjoy learning from your vids! I have the same 2001 with 4.0L. Sounds like piston slap to me also. Same sound just before mine totally bit the dust and began making an awful clangy bangy noise. I tore it apart and saw piston #5 had broke apart. The cylinder scars were too deep to be machined so I got another engine. Piston slap is very common on these 4.0's. Some folks can get bookoodles of miles living with the slap as long as it's not very loud like your vehicle was.
Guess I'm kind of a shade tree guy.. but a long screwdriver held to ear on each rocker arm while running would isolate the noise close to where it is coming from. That noise sounds to me like a lifter collapsed ?
Tom Nawman used this trick to find a bad pulley stuck a screwdriver in an old milk jug cut in half soon a I touched the bad pulley amplified the sound made it easy to track
To this; I just found the likely cause of this problem. I began having a tapping noise in Orlando, by the time I drove back to Macon, it had become more of a knocking noise. I checked the lifters and flex plate, as you had. They were just fine. I pulled the oil pan and found bits of a piston skirt. It turns out to be the no. 6 piston, lost half of it's circumference in piston skirt. This explains why the noise seemed to come from the back of the engine. The fact that the engine continued to run with half a piston in the oil, is testament to the engineering and design of these engines. Will be rebuilding.
+Philip Chafin Totally rebuilt mine with valve job and block cylinders honed, and block cleaned. $1200 total. Engine was in fantastic shape. The cam had usual wear after 100k. Just the broken piston skirt for no apparent reason.
+Steve Curtis I finished the rebuild about a month ago. I replaced the pistons and bearings and had the valves and valve seats ground, and port and polish. It runs a little better than before with about the same horse power and mileage. I would not suggest a port and polish, as it offered no real improvement. apparently, the heads on the 95 are a better design. if I were rebuilding again, it would be a swap/rebuild with a 95 4.0.
I had the same problem and it was the intake valvle, the piston no.5 have no compression and sounds like that, if you have the same noise you must check the compression on each piston
Despite the fact that this video was a half hour long, I'm glad it was here. I have been searching for an 01 valve cover gasket video and all I've found other than this video are 99 and older jeeps with the 4.0. The layout of some of the lines laying across the top are different on the 01 and I wanted to see step by step on my car. Glad this was here 😊
Sounded like a bad lifter tap. These engines as they get older start to sound like diesels lol. The hydraulic lifters are common to sludge up on these older style engines. But another bad sound is the piston slap. So hopefully the lifter.
Quick tip - Diagnostics in less than 30 seconds. Take a longer screwdriver in hand (steel rod, or anything similar) so that the handle does not protrude from the top of the fist. Lay the lower side of a screwdriver on engine (cylinder head, engine block, or any solid part of the engine) lean you head(ear) on fist and listen. You'll be able to hear inside the engine. Actually you'll be able to determine in which cylinder is the problem and whether is in top or bottom part of the engine.
Eric, I was very surprised to see you button everything back together and give up so easily? You didn't even pull the plugs to have a look and test compression, didn't pull the oil pan to inspect bearings in the lower end. Those two would've been first on my list to check for a sound like that, before pulling the valve cover. You simply assumed it was a lifter? Was there a reason why you would discount such a nasty noise without verification and hand the keys back to the customer?
I have owned several Jeeps with the 4.0, One being a 2000 Grand Cherokee that had 342,000 miles before I sold it, never an issue. If the ticking is an issue, use some Seafoam in the crank case, about 1/3 bottle and idle or just drive about 20 minutes and change the oil, gets rid of any gunk build up. The 4.0 was and will always be a great engine that lasts!
As I'm sure several other guys already are hinting I tell my story anyways. It's the valve hydraulic lifters. It usually happens when the vehicle sits for a long time. It then helps to run the car hard. If not change the oil and/or use some oil treatment (Wynns?). Last resort is to change all the lifters.
This is such a common issue with these 4.0's. A local "Jeep guy" suggested that it's a sticky lifter. He said to let out a quart of oil, replace it with tranny fluid (because of the high detergent in it) and run it that way for a week or so...then change the oil. I never had the courage to try it, though.
Thanks for the video Eric; I was hoping you had identified the noise, as the tick on my '95 Grand Cherokee suddenly became more pronounced. With the engine cold, I stuck my finger through the oil cap and noticed there is a lot of side-to-side play on one of the rocker arms. It looks like there is not any play on yours in the video, so I believe one of the arms may not have been tightened properly. I guess I won't know more until I rip the valve cover off.
Mine has been making that noise for years. Mostly when it's cold outside. I can usually shut it off and start it up again and it's gone. I've decided not to worry about it because I've yet to meet someone who knows for sure what it is.
Im a live in a Jeep family and my uncle had a Cherokee with over 400,000 miles. Never had a serious engine issue like the one in the video and I personally owned a Grand Cherokee that I owned until it hit 200,000 miles. Never had a problem with it. Just regular maintenance. Theres always that engine out there that just didn't want to cooperate.
Had a friend buy a 99 Cherokee Classic, and the previous owner had to replace the engine from exactly this problem. It was a lifter that broke down to the point that the intake valve no longer engaged resulting in a dead cylinder. It was run this way for a long time until the the dead cylinder did it in. Ultimately, changing your oil and making sure you ALWAYS hit the full mark on the dipstick will prevent this problem. AMC did a great job with this engine, no doubt about it.
Old school trick is to use a piece of cardboard along the side of the rockers so any oil splashes up it runs back to the head. I have seen valves adjusted on running engines this way to save a lot of time turning engine around and around. Never put anything in the pushrod holes.
Just changed my water heater inlet tube (rusted/bubbling) but to do so, had to remove the valve cover, alternator, thermostat. Your video gave me the know how & confidence to tackle this myself as a lay person. And in 95 degree Mississippi heat. Thank you for making your videos. You show people how to free themselves.
a long heavy screw driver works well as a stethoscope and isolating engine noises just holding up to the engine and listen for the noise or it's just as well when it's a lot cheaper
There is only one point when the rocker will be loose and you can check it for play. You have to rotate the crank to find when that rocker is loose to check for excessive play.
the only way to check the pushrods for play, for a bad lifter or warn cam lobe, is the cam has to be on the base circle to check the pushrod. So start at cylinder #1 and rotate the engine until the intake valve is at full lift, then check the exhaust rocker and pushrod for play, then rotate the engine until the exhaust valve is at full lift, then check the intake rocker for play. for each cylinder if one rocker is at full lift then the other valve is on the base circle of the cam, keep going through all the cylinders and hopefully you will find the one that has more play then the rest, you can also spin the pushrod and if there is one that spins really easily compared to the other ones then thats your bad one.
Soooo all this and zero diagnosis.. great, I wasted my time watching you ultimately change a gasket and grommets.. bet the customer is going to be highly disappointed..
Sure could but with standard hydraulic lifters like this engine, there's no adjustment. The lifters kind of act as shock absorbers and provide the 'clearance'. So, if the lifter is not pumping up, you get excessive 'clearance' and the noise results. Regards, Brad.
I tell you right now the cure for that engine is a new set of lifters they obviously it one time for or another they lost their prime for whatever reason and they have been driving it like that for a while let's hope it hasn't mushroom the bottom of the lifter and you can't get it out then you got a whole engine and take him out from the bottom after you pull the cam been there done that used to work for Chrysler Dodge Jeep and eagle
My cherokee sport 2000 model not sending oil to the rockers arms, done know wat to do. I just change the oil pump and stay no oil coming up to the rockers.
great vid, I didn't read all the comments but from the starter video it looked like there was oil possibly from the rear main seal. Possibly the main bearings were worn causing the leakage from the rear main seal and eventual noise then failure. Thanks for all the great vids.
Carlos Aponte first I've heard of them braking piston shirts, but I'm not as familiar with the 4.0s yet. 4.7, might be oil but it just happens to nearly all of them. Its always cylinder #8 from what I've seen /heard, mine started banging so hard you could feel it in the floor. Only 128k miles. It sat for awhile now it has a dead transmission and electrical problems, it's always something.
Sounds like my first 89 cherokee. Had that noise for a long time. A couple points Im sure you know, but I figured I should mention them. The 4.0 uses CCV, not PCV. There is no PCV valve, just two "Metered Orifices 99-01 4.0s have the 0331 head and are known for head cracks between the middle cylinders. The heat shield wasnt added until some time after 97, to prevent heatsoak/vapor lock in the middle injectors. The 4.0 is a really good motor if its taken care of, my new 89 has 245k on it now.
I had a similar noise on my 98 zj with just over 200k miles. I replaced all the rocker arm pivots and it still did it. Then my distributor rotor hit the cap, leaving me stranded, and I realized that the distributor shaft was worn and loose. I replaced the distributor and it went away. My guess is that I was experiencing some kind of bad detonation from a loose distributor rotor shaft? Don't know if this will help anyone but consider checking your distributor rotor shaft for any play
I have a 4.0L with intermittent lifter-related & piston rod noise. Add 2 qrts oil to crankcase, total 8. There has been no problems doing this. Stops knocking, rod noise, lifer-related noise - until you can do repairs. Oil level is still below any piston hydrolock. May not apply to other engine. Have manual trans, can feather clutch in low gear to slow rpms for initial seconds to avoid metal noises til oil is flowed throughout. Each qt raises oil level about 3/4" above top fill line if you add 2 qts startingv with oil at top. Never run an engine with any of these noises without first having oil level at top "fill" line on stick.
You can use rocker arm "deflectors" that clamp onto the front of the rocker arm and covers the hole, DEFLECTING the oil. I still have a couple different sets I use to use on the chevy engines I worked on in my HOT ROD days. Their much better then paper clips, with no worry of damaging anything. And the old silicon/cork gaskets would stay in one piece, compared to just a straight cork gasket. Good video. I have the same engine in my Cherokee and am starting to get a similar noise. Noise could also be an exhaust leak, so check both.
Wrist pin. Very common with the 4.0 the tap can start anytime after the 100,000 mile mark. Mine has sounded like that since I bought it 20k ago, I'm about to break 200k, it is a 96 so it had a tougher block than the newer ones, but I've spoken to more than just a few jeep owners who've had the same tap all of them said the same thing "It's a jeep thing". Also more than one mechanic has told me that it isn't worth fixing unless the noise bothers me that much.... I just tell people I like driving around behind my own personal drum line .
No need for paperclips either. With 200k on the motor, the oil pressure will be low anyway. It's not going to drain the oil pan at idle to check the rockers/lifters. You just don't want to add any oil to it.
just a light ticking noise is normal for jeeps. the lifters give out, but if it sounds like a rattle or metal hitting metal than it is not good at all and should be looked at. the lifter issue is more money than it is worth to fix. most jeep owners just deal with it. the head has to be pulled to change lifters in the 4.0. how ever if it is like you say you might be able to get away with a motor flush to help free the collapsing lifter.
So my 2001 jeep 4.0l had the same exact noise. I did the same thing, thinking it was the rockers or the valve or lifters. All that looked good. So I bit the bullet and got a jasper engine. Swapped it out. After tearing the engine apart I found piston 2 skirt was cracked. The pieces were in the pan. Prior to the noise issue I had some overheating problems. The electrical fan seemed to be a issue. It would work intermittently which made me miss diagnose the problem. I think all the overheating issues made the piston fail. After installing the engine I installed a mechanical clutch for reliability. The only issue I have now is that its over cooling cause I installed a Escalade fan blade that has 11 blades. I think it's overkill now. So I'm going to install a stock fan blade. The 4.0l in the wj jeep is very disappointing cause its supposedly a reliable engine but by them installing a electrical fan and putting the catalytic converters so high up and close to the engine doesn't help with keeping it cool. Bad design on the later model jeep. The older ones are the way to go. If I would of known what I know now. I would of got a 04 v8 HO overland but I've invested too much in mine i can't get what I put into this one so I guess I'm stuck with this junk till she dies again. I hope this helps bring some closure on that vehicle. I know how much you care about quality repair. As do I.
I agree on cleaning out the holes but that oil will never cause the bolt to stop from getting tight oil will simply get squeezed out because automotive threads are not air or liquid tight.
I have Jeep the exact year and trim as the model you're working on in this video. Mine has 215,600+ miles on it and the vehicle can't go past 70 mph without it feeling like something is yanking it back. Brand New transmission suspension, front end, rear end all looked at. Can You give me a quick guess on whats gonna go next or if its time to get a new vehicle?
The lifters are bad the sound is significantly higher pitched. The lifter collapses internally. Put a quart of transmission fluid in it let it run 30 minutes at idle then change the oil. Many times carbon can get stuck inside the lifter.
1 minute in, I'm thinking valve clearances - noisy tappet. 20 minutes in I'm thinking check them. 25 minutes in, I'm thinking Eric will not be defeated. 30 minutes in, I'm in despair and about to give a thumbs down. Then I read the description for the video - 2001 car, long mileage, not worth the cost in labour to further investigate. Thumbs up! Great video and explanation. Hope you find out what did for it. We can only guess until you dissect it - if you can find it again. Great entertainment!
Eric, I wish I had seen your video two days ago! I did my 2000 GC 4.0 valve cover gasket yesterday after watching other videos and reading about it for a couple of months. The problem is all the info I collected wasn't for the GC WJ model. The other videos didn't have the resonator (down-stream from the cleaner), heat shield or that cable trough, plus they didn't show a GC with the last 4 bolt/studs under the windshield. Some questions, how long would you say it takes to do just the valve cover gasket change (minus the tick diagnosis)? I got most of the bolt/stud out in maybe 30 minutes, but that last one on the driver side took another 30 minutes. 85inch/lbs = ~7ft/lb (just divide in/# by 12) and most torque wrenches don't go down to 7ft/# so how did you get the right torque for the cover? (I just guessed that pulling this hard at 11" is like lifting a bit less than gallon of water (8.331#). What pattern did you follow when tightening (to 85in/#)? The service manual only shows 14 bolts/studs, but mine had 15. (I still kept the basic pattern moving clockwise starting with the center one on the passenger side.) You used the Fel-Pro gasket and one of the 15 rubber grommets is different. Where does it go? (I'd think maybe the grounding strap stud, but wouldn't that help to isolate the ground making it less grounded? Maybe the coolant hose? Any idea why so many studs? Only 3 of ?8 (I lost count) seem to be used on mine (coolant hoses, ground and cable in the back passenger side). You said the bolt on the resonator was a 10mm... but what is the thread count and bolt size? Mine was missing so I'd like to replace it, and the bolts/studs from the valve cover are too big. By the way, the VC bolts/studs are a 1/4-20 into the valve cover body. I even measured them with a thread gauge. Metric my (*&)*(!% The nuts are 11mm, but I found the next closed SAE (7/16) fit tighter. I enjoyed confirming that you and I both took off the resonator to get it out of the way and to detach the VC line from the manifold. I could not get it off the VC end and didn't want to break the plastic. I already split the other line into the resonator at the VC end. (Thank God for silicone "repair" tape until I get a new one.)
Been mentioned many times but that does sound like rod knock, although I have not heard it coming from that specific engine. Engine sounds like this resonate it makes is really hard to find the source. But usually if you can't find the specific location, it is from the engines internals. Hopefully at some point we'll find out what the problem is, another excellent video as usual although I think your A/C vid was your best so far.
My 99 Jeep cherokee 4.0 has the exact same noise. I thought possible flex plate bolts- they were fine. I noticed when I changed the oil the oil felt very gritty. Did a compression test and all pistons were within normal spec although #6 was at low end of spec. Vacuum gauge held fine . Took off oil pan and found chunks of piston skirt in the pan from #6 piston. The rings had worn as a result and scored the cylinder wall a bit. The engine had 290,000 miles so I’m gonna yank it and do a stock rebuild.
99 to 02/04 The perviously bulletproof 4.0L was turned into CRAP. They changed the castings on the pistons, and the head. The Piston skirts tend to crack off and shortly there after it blows up... There is a defect in the head castings I think between cyl 5-6 and it will weep coolant into the valve area. Usually slow enough that you may not see a color change in the oil, but it will mysteriously loose coolant. The 4.7 V8 has issues too... mostly dropping the Steel valve seats out of the aluminum heads if they thing overheats even just a little. 93-98 had more robust engines.
The oil port for the lifer is plugged. They all do that for some reason. My guess is a hot spot in the oil port. Pull noisy lifter out, start motor for a few seconds enough to blow oil . Put lifter back in and it's fixed.
it is one of 2 things the jeep 4.0 is known for... 1 a rod bearing is to warn. you will still have decent oil pressure, just the knock like this one has. 2. a broke piston/piston skirt. it will also make noise like this.. just went through option one with my 96 jeep 4x4 4.0 i lucked out. pulled the oil pan and replaced all the rod bearings. problem is now fixed and runs like new.
hey eric, I have this noise that is definitely in time with the valve assembly. the odd thing is that it comes and goes. does this seem likely? in my experience with motor internals, once they go, they go. what do you think? pull the valve cover and take a peak?
If the problem is a sticky lifter it might be marginal and sometimes the lifter sticks, sometimes it doesn't. Do you know the history of the car? If it hasn't had its oil changed like it should have been you might give it some extra oil changes... say once every thousand miles or so for a while and see if the problem clears up.
I just had this happen. #3 piston skirt broke apart. It still had good power because it still sealed, but was sloppy in its motion. The skirt pieces were found in the bottom of the oil pan.
The seated harness assembly is what got me. It looks as if the bracket that holds that in place is bolted onto the fasteners.. and the only way to remove them is to break them. Ill have to take another look at it. Good idea using the 45* pliers.
I changed the head gasket on one of them last year. Took me 45 minutes to remove the cylinder head. A little longer to put engine back together . Very easy!!
My 04 does the same exact thing at start up, it's been like that for almost 2 years. 108,000 miles and still running strong. No other issues at all. I'm afraid of a broken piston; then again, so far I haven't heard of anyone having a catastrophic failure. That's one dependable little engine.
Awesome video =D My 01 4.0 Jeep Grand Cherokee was doing the same thing and I figured it was the lifters. Now it's gotten to the point that when I turn it on, its super load and may have damaged something else internally. The engine has 198,000 and just replaced the tans about a 2yrs ago. So when this happened I said I had had enough and wasn't going to rebuild the engine. Now its just sitting in the backyard and I decided to buy a 2012 Toyota Prius C, which 51mpg versus 16 with the Jeep.
GAH! This is just like the Diary of Ann Frank. It ends abruptly and its all bad news. Well it was good seeing the removal of the valve cover. I have a 98 Grand Cherokee and sure would love more videos on dem Grand Cherokees. That paper clip trick was spectacular!
Pull the oil pan. Simple job on that model and engine. You can then check for rod play and inspect the pistons. I would agree and checked the top end on the last 4.0 with a noise like that hoping for the best, but it sounds lower. The last one was a broken piston skirt and it seems common. Threw a set of new pistons in it without even pulling the engine. I thought the paper clip might be a good idea until you struggled to get some out. .. they make a universal rocker arm cover set that clips on to block the oil. I had a set at one time, but no idea where it went. I guess its been 10 years since I thought I might need it .lol
Dear Eric, this noise might be a cracked or loose torque converter plate (flex plate) . Other possibility try listening to the noise from the oil pan, as it might be a rod knock which may require bottom end bearing. John Kaplanian
Eric, I have a 1998 4.0 (212k) and have the exact same sound (at all RPMs). If I backed off the torque on the rocker on 2nd rocker from the front, the sound went away completely. Performed a full top end job with new lifters (oil soaked before install), push rods, resurfaced the head, compression checked, all good, all back together. SAME SOUND! Sound is coming from the lifter just as it was before head job (stethoscope to find the sound) so my theory is it's a worn cam lobe and the lifter is slamming down creating the sound. With out pulling and replacing the cam, how can I run the engine as is, with less torque on the rocker bolt to alleviate the sound?
Spring may have a weak point not allowing the strength to pushing the lifter on lob hard.so it's possible when you loosened the spring can now again push in a different spot on each coil of the spring.could be sticky lifter.run marvel mistory oil a new oil then loosen the rest like you did .if possible put back where nut was.my 2000.cherokee 4.0 has a lifter that makes a little noise .but after 2 mins it go away.4.0 s like zink .shell.oil I roseshella I think number 5 there a vedio.erric s cousin did one.the guy w beard.im tired .lol
eric, the fast way to isolate a noise to a cylinder would be revving the engine of idle, disable spark one by one until the noise goes away. So when the noise goes away after disabling say the cylinder two; then you know it that cylinder. Then from there is just a matter of top or bottom apart of the engine.
I have a 1997 with the same noise. look up timing adjustments. I had to realign my timing marks, and set first piston at TDC. Then I removed distributor, and realigned it to the correct setting. my engine was off by 5° and the plugs needed to be gapped properly. Noise is gone, been like that for a year now. runs like a champ.
I almost acquired a 2000 GMC Yukon Denali ala 5.7 vortec V8 about a year and a half ago, with about 250k miles, that made a similar noise. My father in law and I argued over what the source could be, he said "rod knock" while I suspected loud lifter tick. Turned out to be a spun bearing making the noise. Supposedly whatever "technician" that worked on it before, forgot to put oil back in the engine before starting it up which is what caused it. And yes, I passed on the vehicle.
Bought (cheap) a 2001 Cherokee with that noise. Engine ran fine. Dropped the oil pan and #4 piston had broken skirt. Also found casting material in engine when replacing freeze plugs when engine was out.
I have a 2001 just like this one and it started with a slight ticking sound and then got worst, sounded just like this one. Finally the motor locked up, these 4.0l engines are notorious for cracked piston skirts due to design flaws. I bet if you drop the oil pan you would find pieces of a piston. Mine had a broken rod and piston skirt with another one that was cracked.
When checking for noise, take the valve cover off and then put each cylinder on top dead center and check the intake and exhaust rockers for play. this is the easiest way to find out if you have a worn lifter, bent push rod or worn rockers. If everything checks out, pull the oil pan and check for broken piston parts.
Hi Eric, Thank you for the video, apart from the views of the inept commenters, this is definitely a collapsed hydraulic lifter issue. It is a common misconception that a heavier motor oil will assist the hydraulic lifters to "pump up" so to speak, for example 20w50. I have solved lifter issues by running a lighter oil such as 5w30 and have physically heard the point at which the lifter has quieted down, it is always important to run the oil that the manufacturer specifies, don't just say oh wow the Valvoline Racing 50 is on special today when your engine requires 10w30 of course if the lifter has been collapsed for a period of time then it will be damaged and require replacement, 25 years in the automotive repair industry has taught me to replace the oil first that is your cheapest option and then run the car at cruising speed for 50 miles or so, if the problem persists then it is money spending time. I think that its great that you put yourself out there for public scrutiny so that we might all learn something together. Thanks Eric
have the same noise i have rolled rod bearning in and after idling 20mins the knocking sounds is back.so i used my long screw driver and found the location of the racket comming from the area of the last 2 cylinders under the value cover,any good videos you can suggest on how to aproch this ofcourse im gonna pull the value cover this morninr...
@@frankholtzclaw765 interested to know how yours turned out. This guy did a great job diagnosing and fixing: th-cam.com/video/VAkmlvW9fYA/w-d-xo.html
Just wanted to share an experience I had with an '88 Jeep Cherokee that was making very similar engine noise to the one in your vid. After watching several similar vids on youtube I was pretty much convinced the problem was piston slap or the like and was about ready to junk it when I stumbled on the actual culprit. Turned out to be the power steering pump. Pump had been losing fluid and apparently gotten low enough to do serious damage. Apparently, the idler pulley also sustained some collateral damage as well - the bearings were seizing up - some actually torn up and jammed. I replace the steering pump and reservoir and the idler pulley and the horrible noises disappeared immediately. Running like new now - or as close to new as a 4.0 liter with 248k miles can run. I think this shows how difficult diagnosing engine noises can be. I would have bet anything that mine was related to engine internals.
This is definitely not a power steering pump. It is most likely the pistons slapping around due to rings being gone. Check compression and that will be a determining factor if you have a bad rod bearing or worn ring. I think it's a bad rod bearing in that case the motor needs to be rebuilt
Yikes
Mine sounded just like that and it was a loose torque converter bolt hitting the block. Tightened it and others up and it went away. At first I thought it was a rod knocking because it sounded like it was coming from the lower rear of the engine but then I read somewhere to check the torque converter bolts.
I've heard of this also, good to let people know.
Thanks just discovered wife’s Jeep doing same thing. Ill check that out
+1 for this. I had a terrible knock I literally thought a bearing was exploded. Ended up being this.
@@firingallcylinders2949 I literally just picked up a 99 WJ 4x4 just now and it was (what I think/thought) tapping the top of the valve cover but sheesh now I want to check this out with the tq bolts everyone is talking about. First jeep, $500, drove me home tapping everywhere 20 miles home lol.
k! Amazon in kknjjnnmjjjjnnjjjjnjjnnnnnnnnnnnnnjjnnkkkkkmmu! ttyhhnn
Had that noise in mine around 275,000 mi. I lavished it with over the counter oil additives and cleaners of every sort. Around 250 mi later the noise was gone. Not saying anybody should try this but it was the best choice for me at the time. I've really pounded my Jeep 4.0 High Output. Towed massive loads regularly. Blew the small radiator and switched to bigger. When you overheat go ahead and replace water pump. Due to oil leaks I've run it very low on oil several times. This engine gained my respect and I now baby it. It is at 400,000 mi now and the only work on it was replaced timing chain. That's one timing chain in 400,000 mi...amazing. Knock on wood. The oil leak probably helped keep the oil clean. It's fun to think do I want to rebuild and make everything perfect, or wait and see how long it will last. I know several people who dislike the engine. As far as I'm conserned it's bullet proof...knock on wood.
How's the engine now?
Actually, these engines are amazingly well engineered and built. This is why they had such a long run with AMC, then when Chrysler bought the Jeep brand, continued to produce them with minor modifications.
I saw the comment about the head weeping antifreeze between the #5 and 6 cylinder. This was corrected in 2003 with the TUPY 331 head. I have an '04 JGC with the 4.0 inline 6 with 230k miles on it The timing chain is still quite as the day it was new. No oil use whatsoever...but I have maintained this vehicle better than the dealer manual suggests. A big plus is flushing your antifreeze every 30k and also use nothing but Royal Purple 10W-30. So at 230k, she is still in her teenage years.
Let me get an update. I just bought a 04 limited 4.0.
@@Bojuh I now have 300k plus miles on it. My '04 Grand Cherokee still runs like new.
The change was actually made in 2002, the original 0331 heads have a tendency to crack between #5 and 6. The head that replaced it is identical except for the area that cracked being modified (thicker if I remember right) and a TUPY forge mark visible on that spot as well.
@@trakkerp4202 Thanks for the correction on the year. My earlier research said 2003, but now I know it was 2002.
Dude the reason the paper clips got stuck is because that's a ball and socket and when you stick the paper clip down in there that feed hole moves back and forth go out and get you some rocker arm shields that you just clip right to the rocker rocker arm and it diverts the oil snap on Mac or Matco safest way to go never stick anything down a pushrod hole you're just asking for trouble
izzynutz2000 you are correct, that is prob why the engine blew after he worked on it....Id never let him work on my jeep after seeing that, its was kinda of funny when he said, on they get a little stuck, Blahhhh ha
even a pos shitty jeep with a 4.0 i6 will last longer and go further than any other car out there, rain snow sand mud or flood, a jeep will get you there, at least a real jeep not this new fiat bullshit, and you will have more fun doing it. and don't forget that the jeep along with harley davidson helped america win wars, so to say fuck jeeps, is like saying fuck america, and fuck freedom, so you can take your nazi bullshit to fuckkity off land and take your little bitchmobile with you
I have a 98 Jeep GC with a 4.0L engine. I bought it new. Did all the maintenance myself. Only used Amsoil lubricants. So far I had no issues with the engine or anything else. I did a lot of towing and off-roading with it. Great reliable vehicle. I've owned a lot of Hondas and Toyotas, The Jeep has been a lot more reliable and very capable vehicle. Can't say this about my 2010 Tacoma. Hondas were the worst POS.
Andrew Ivanov
Well, you were the exemption to the rule, because statistics show otherwise: Hondas and Toyotas are the most reliable vehicles and the most cheap to maintain.
Toyota's YES, Honda's NOT SO MUCH.
I count about 8 "ticks" per second, or 480 a minute; assuming it's idling at just under 1000 rpm cold, that means the ticking frequency is 1/2 the engine RPM. Wouldn't that indicate a valvetrain issue? I'd expect a piston problem to sound with a frequency matching the RPMs.
Piston only fires every 4 strokes. Its possible it coincides with "firing" event, but that's a great assessment and very possible it's just Valvetrain.
Your patience with the quirks of automotive design is inspiring.
also for those having a knocking in the engine. on some models there's a knock sensor that will eventually fail.
causing the low end knock.
there's also camshaft position sensor and crankshaft position sensor. if,any of these are bad, a knock will occur.
What years ?
@@sticrzy123 my 05 had that exact problem! 4 liters are fun, most of them make all sorts of noise
That engine oil is darker than my morning coffee
Needs an OIL CHANGE BAD & it's down about a quart looking at the dip stick mark to begin with.
I like my coffee like I _seem_ to like ( or mistakenly pick) my women.... _Cold & Bitter_ ...
😬😑😔😞🤧
I tell everyone to do their oil changes every 3k. It could have saved that engine probably. Lack of maintenance kills me. Its like throwing 5k in the trash. Cause now they going to need another vehicle.
Was that the milage since the last oil change?
@@James-kc3gw 6 year old reply.....its alot of miles bud, hell I sold the 4.0 8 years ago
I'm surprised he didn't even go under the car. I have a sound just like this on my xj 4.0 and at first thought it was the motor. Went under the engine and it was coming from the bell housing. It's pretty common for the flex plate bolts to come loose, and the flex plate can crack as well.
I've had this happen to my xj 97
These 4.0s are notorious for cracked piston skirts. That was a pretty loud "tap" and I would be willing to bet it was piston slap rather than a lifter.
Joey Quigley you are correct. Also, when the noise is just like in the video, it is in fact a piston. I know from experience, drove almost a year with this tick and finally the piston skirt blew. It was ultimately caused from non existent oil changes from the previous owner. Ended up getting a new engine.
***** Mine currently has it as well. I'm just waiting for it to go =/.
Joey Quigley Ugh, sucks. On the bright side, after I blew the piston it got me home and then to my buddies/mechanics house...about 40 miles... loud as hell lol. And, we started it up again and ripped it a few times down the road. Tough ass engine. PLEASE CHANGE YOUR OIL PEOPLE!!!
Same here. Ran fine for about a year then - one loud bang and the motor cut out. I restarted her and drove home, about 15 miles - trailing lots of smoke and oil. On inspection, found that the #2 piston was gone, totally disintegrated and the rod had cut groove into the cylinder wall. The remains of the piston had knocked a large hole in the sump cover. Tough ass engine as you say, but better have it checked out before you blow that piston.
Is just luck of the draw as mine has 263k miles on it but don't know if anything been done to it previously
That heat shield under the fuel rail is to prevent vapor lock, common on 2000-above Jeep 4.0's
Yeah about 5 years late on this one but I was thinking the same thing whenever he called it a “heat shield” and only a heat shield because that’s when most backyard guys will say blah don’t need this anymore....lol but you do it’s to prevent the injectors from becoming heat soaked and causing further problems we don’t wanna fix one problem to create 2 more
This is what happened to my jeep. Thanks Eric. I left it parked on the side of the road. It had that knock and I saw a puff of white smoke from engine bay and it didn't blow a rod or anything just seized up. Wont even turn over.
Exactly what I hear in my 2001 Jeep Cherokee limited
My 01 Jgc is sounding just like that, local mechanic said could be lifter or rod. Video is very helpful
Thanks Eric! I always enjoy learning from your vids!
I have the same 2001 with 4.0L. Sounds like piston slap to me also. Same sound just before mine totally bit the dust and began making an awful clangy bangy noise. I tore it apart and saw piston #5 had broke apart. The cylinder scars were too deep to be machined so I got another engine. Piston slap is very common on these 4.0's. Some folks can get bookoodles of miles living with the slap as long as it's not very loud like your vehicle was.
Guess I'm kind of a shade tree guy.. but a long screwdriver held to ear on each rocker arm while running would isolate the noise close to where it is coming from. That noise sounds to me like a lifter collapsed ?
Tom Nawman used this trick to find a bad pulley stuck a screwdriver in an old milk jug cut in half soon a I touched the bad pulley amplified the sound made it easy to track
With my luck the paper clips would fall off and into the engine.
To this; I just found the likely cause of this problem. I began having a tapping noise in Orlando, by the time I drove back to Macon, it had become more of a knocking noise. I checked the lifters and flex plate, as you had. They were just fine. I pulled the oil pan and found bits of a piston skirt. It turns out to be the no. 6 piston, lost half of it's circumference in piston skirt. This explains why the noise seemed to come from the back of the engine. The fact that the engine continued to run with half a piston in the oil, is testament to the engineering and design of these engines. Will be rebuilding.
+Philip Chafin Totally rebuilt mine with valve job and block cylinders honed, and block cleaned. $1200 total. Engine was in fantastic shape. The cam had usual wear after 100k. Just the broken piston skirt for no apparent reason.
+Steve Curtis I finished the rebuild about a month ago. I replaced the pistons and bearings and had the valves and valve seats ground, and port and polish. It runs a little better than before with about the same horse power and mileage. I would not suggest a port and polish, as it offered no real improvement. apparently, the heads on the 95 are a better design. if I were rebuilding again, it would be a swap/rebuild with a 95 4.0.
I had the same problem and it was the intake valvle, the piston no.5 have no compression and sounds like that, if you have the same noise you must check the compression on each piston
Beto: que tal quedo after you fixed.???
Despite the fact that this video was a half hour long, I'm glad it was here. I have been searching for an 01 valve cover gasket video and all I've found other than this video are 99 and older jeeps with the 4.0. The layout of some of the lines laying across the top are different on the 01 and I wanted to see step by step on my car. Glad this was here 😊
Sounded like a bad lifter tap. These engines as they get older start to sound like diesels lol. The hydraulic lifters are common to sludge up on these older style engines. But another bad sound is the piston slap. So hopefully the lifter.
frankly both are very common especially on later model inline 4s, like th 05 to 06 models.
i
Quick tip - Diagnostics in less than 30 seconds.
Take a longer screwdriver in hand (steel rod, or anything similar) so that the handle does not protrude from the top of the fist. Lay the lower side of a screwdriver on engine (cylinder head, engine block, or any solid part of the engine) lean you head(ear) on fist and listen. You'll be able to hear inside the engine.
Actually you'll be able to determine in which cylinder is the problem and whether is in top or bottom part of the engine.
Eric, I was very surprised to see you button everything back together and give up so easily? You didn't even pull the plugs to have a look and test compression, didn't pull the oil pan to inspect bearings in the lower end. Those two would've been first on my list to check for a sound like that, before pulling the valve cover. You simply assumed it was a lifter? Was there a reason why you would discount such a nasty noise without verification and hand the keys back to the customer?
I have owned several Jeeps with the 4.0, One being a 2000 Grand Cherokee that had 342,000 miles before I sold it, never an issue. If the ticking is an issue, use some Seafoam in the crank case, about 1/3 bottle and idle or just drive about 20 minutes and change the oil, gets rid of any gunk build up. The 4.0 was and will always be a great engine that lasts!
Broken piston skirt maybe?
This is what mine sounded like with cracked piston skirts. After the skirt broke off, was MUCH louder.
As I'm sure several other guys already are hinting I tell my story anyways.
It's the valve hydraulic lifters. It usually happens when the vehicle sits for a long time. It then helps to run the car hard. If not change the oil and/or use some oil treatment (Wynns?). Last resort is to change all the lifters.
WOOHOO I love the 4.0 I6...sooo easy to work on
This is such a common issue with these 4.0's. A local "Jeep guy" suggested that it's a sticky lifter. He said to let out a quart of oil, replace it with tranny fluid (because of the high detergent in it) and run it that way for a week or so...then change the oil. I never had the courage to try it, though.
That engine is Knock-knock-knockin' on heaven's door!
Thanks for the video Eric; I was hoping you had identified the noise, as the tick on my '95 Grand Cherokee suddenly became more pronounced. With the engine cold, I stuck my finger through the oil cap and noticed there is a lot of side-to-side play on one of the rocker arms. It looks like there is not any play on yours in the video, so I believe one of the arms may not have been tightened properly. I guess I won't know more until I rip the valve cover off.
ahh the famous 4.0 jeep lifter issue
Mine has been making that noise for years. Mostly when it's cold outside. I can usually shut it off and start it up again and it's gone. I've decided not to worry about it because I've yet to meet someone who knows for sure what it is.
its normal 4.0
15:00 "I'm going to run this engine with the valve cover off" = Mind Blown LOL
Jargon StarCraft yes you can start a car without the valve cover on.... i
Awesome vid. When you had the cover off I was thinking I wish you could run it. Next second you straight away said 'you can!' that just made my day.
My jeeps pcv hose didn't come off that easy, not at all.
+Rewind Same here. Left it in valve cover till later. Just pulled hose.
Im a live in a Jeep family and my uncle had a Cherokee with over 400,000 miles. Never had a serious engine issue like the one in the video and I personally owned a Grand Cherokee that I owned until it hit 200,000 miles. Never had a problem with it. Just regular maintenance. Theres always that engine out there that just didn't want to cooperate.
by the way this my most favorite engine
Had a friend buy a 99 Cherokee Classic, and the previous owner had to replace the engine from exactly this problem. It was a lifter that broke down to the point that the intake valve no longer engaged resulting in a dead cylinder. It was run this way for a long time until the the dead cylinder did it in. Ultimately, changing your oil and making sure you ALWAYS hit the full mark on the dipstick will prevent this problem. AMC did a great job with this engine, no doubt about it.
eric! you didnt solve shit!
LMAO
Old school trick is to use a piece of cardboard along the side of the rockers so any oil splashes up it runs back to the head. I have seen valves adjusted on running engines this way to save a lot of time turning engine around and around. Never put anything in the pushrod holes.
Exactly what my grand cherokee sounded like when my piston skirt broke
did your piston skirt broke after the engine overheated at some point?
@@farerse mine did right after it over heated.
@@watupbih-dawg5682 ok slightly overheat or into the red area overheat?
@@farerse both... I was flooring it when it happened. Idk what to do.
@@watupbih-dawg5682 ok red area overheat is very bad .. maybe best to swap engine
Just changed my water heater inlet tube (rusted/bubbling) but to do so, had to remove the valve cover, alternator, thermostat. Your video gave me the know how & confidence to tackle this myself as a lay person. And in 95 degree Mississippi heat. Thank you for making your videos. You show people how to free themselves.
If you're talking about the metal tube that connects the heater hose to the water pump, it's easier to remove the water pump to replace this tube.
it's the damn lifters man... super common problem!
I agree he don't know Jack crap
Can they get that loud? I think i hear mine barely doing that. Is that noise gradual? With more wear n tear it gets louder or no??
a long heavy screw driver works well as a stethoscope and isolating engine noises just holding up to the engine and listen for the noise or it's just as well when it's a lot cheaper
just empty every pocket
it's a "JEEP" thing.
There is only one point when the rocker will be loose and you can check it for play. You have to rotate the crank to find when that rocker is loose to check for excessive play.
Just throw in some engine restore haha
the only way to check the pushrods for play, for a bad lifter or warn cam lobe, is the cam has to be on the base circle to check the pushrod. So start at cylinder #1 and rotate the engine until the intake valve is at full lift, then check the exhaust rocker and pushrod for play, then rotate the engine until the exhaust valve is at full lift, then check the intake rocker for play. for each cylinder if one rocker is at full lift then the other valve is on the base circle of the cam, keep going through all the cylinders and hopefully you will find the one that has more play then the rest, you can also spin the pushrod and if there is one that spins really easily compared to the other ones then thats your bad one.
I'm pretty sure is a piston gone
I use a stethoscope for knocks. Long handled screwdriver works also.
Soooo all this and zero diagnosis.. great, I wasted my time watching you ultimately change a gasket and grommets.. bet the customer is going to be highly disappointed..
Sure could but with standard hydraulic lifters like this engine, there's no adjustment. The lifters kind of act as shock absorbers and provide the 'clearance'. So, if the lifter is not pumping up, you get excessive 'clearance' and the noise results.
Regards,
Brad.
I tell you right now the cure for that engine is a new set of lifters they obviously it one time for or another they lost their prime for whatever reason and they have been driving it like that for a while let's hope it hasn't mushroom the bottom of the lifter and you can't get it out then you got a whole engine and take him out from the bottom after you pull the cam been there done that used to work for Chrysler Dodge Jeep and eagle
may as well burn your lifter money; rod bearing is gone.....
My cherokee sport 2000 model not sending oil to the rockers arms, done know wat to do. I just change the oil pump and stay no oil coming up to the rockers.
great vid, I didn't read all the comments but from the starter video it looked like there was oil possibly from the rear main seal. Possibly the main bearings were worn causing the leakage from the rear main seal and eventual noise then failure.
Thanks for all the great vids.
Smfh. Its a spun rod bearing i guarantee. I cant believe how many people have never heard one.
Tony W wrong
If you guys say so. Replaced 4.7 rod bearings that were making the same noise. An my 4.0 is almost at the same point.
Tony W well in this case its a broken piston skirt. The 4.0s are notorious for this. How did the 4.7 spin a bearing? Oil?
Carlos Aponte first I've heard of them braking piston shirts, but I'm not as familiar with the 4.0s yet. 4.7, might be oil but it just happens to nearly all of them. Its always cylinder #8 from what I've seen /heard, mine started banging so hard you could feel it in the floor. Only 128k miles. It sat for awhile now it has a dead transmission and electrical problems, it's always something.
Los The Ghost 4.7s are junk lol
Sounds like my first 89 cherokee. Had that noise for a long time.
A couple points Im sure you know, but I figured I should mention them.
The 4.0 uses CCV, not PCV. There is no PCV valve, just two "Metered Orifices
99-01 4.0s have the 0331 head and are known for head cracks between the middle cylinders.
The heat shield wasnt added until some time after 97, to prevent heatsoak/vapor lock in the middle injectors.
The 4.0 is a really good motor if its taken care of, my new 89 has 245k on it now.
My 1993 has 225,000. It's bullet proof.
When you change the oil regularly & keep up Maint. DAMN STRAIGHT.
still have it?
I had a similar noise on my 98 zj with just over 200k miles. I replaced all the rocker arm pivots and it still did it. Then my distributor rotor hit the cap, leaving me stranded, and I realized that the distributor shaft was worn and loose. I replaced the distributor and it went away. My guess is that I was experiencing some kind of bad detonation from a loose distributor rotor shaft? Don't know if this will help anyone but consider checking your distributor rotor shaft for any play
251k and still going strong lol
You clearly don’t have the 99-04 Jeep motor....
I have a 4.0L with intermittent lifter-related & piston rod noise. Add 2 qrts oil to crankcase, total 8. There has been no problems doing this. Stops knocking, rod noise, lifer-related noise - until you can do repairs. Oil level is still below any piston hydrolock. May not apply to other engine. Have manual trans, can feather clutch in low gear to slow rpms for initial seconds to avoid metal noises til oil is flowed throughout. Each qt raises oil level about 3/4" above top fill line if you add 2 qts startingv with oil at top.
Never run an engine with any of these noises without first having oil level at top "fill" line on stick.
broken piston skirt
You can use rocker arm "deflectors" that clamp onto the front of the rocker arm and covers the hole, DEFLECTING the oil. I still have a couple different sets I use to use on the chevy engines I worked on in my HOT ROD days. Their much better then paper clips, with no worry of damaging anything. And the old silicon/cork gaskets would stay in one piece, compared to just a straight cork gasket. Good video. I have the same engine in my Cherokee and am starting to get a similar noise. Noise could also be an exhaust leak, so check both.
To loud to be lifter
Oldcoinsandstuff1 cracked piston skirt(s)
Wrist pin. Very common with the 4.0 the tap can start anytime after the 100,000 mile mark. Mine has sounded like that since I bought it 20k ago, I'm about to break 200k, it is a 96 so it had a tougher block than the newer ones, but I've spoken to more than just a few jeep owners who've had the same tap all of them said the same thing "It's a jeep thing". Also more than one mechanic has told me that it isn't worth fixing unless the noise bothers me that much.... I just tell people I like driving around behind my own personal drum line .
captainspyke I have the same exact tap/knock on mine and have put 50k on mine as well....
captainspyke Mines done it for like 100k miles. It's got 215.500 now, how long will it be able to keep doing it?
+captainspyke My AMC Comanche started making that noise around 260,000 miles and could not figure it out. 5K miles later it threw a rod.
No need for paperclips either. With 200k on the motor, the oil pressure will be low anyway. It's not going to drain the oil pan at idle to check the rockers/lifters. You just don't want to add any oil to it.
just a light ticking noise is normal for jeeps. the lifters give out, but if it sounds like a rattle or metal hitting metal than it is not good at all and should be looked at. the lifter issue is more money than it is worth to fix. most jeep owners just deal with it. the head has to be pulled to change lifters in the 4.0. how ever if it is like you say you might be able to get away with a motor flush to help free the collapsing lifter.
So my 2001 jeep 4.0l had the same exact noise. I did the same thing, thinking it was the rockers or the valve or lifters. All that looked good. So I bit the bullet and got a jasper engine. Swapped it out. After tearing the engine apart I found piston 2 skirt was cracked. The pieces were in the pan. Prior to the noise issue I had some overheating problems. The electrical fan seemed to be a issue. It would work intermittently which made me miss diagnose the problem. I think all the overheating issues made the piston fail. After installing the engine I installed a mechanical clutch for reliability. The only issue I have now is that its over cooling cause I installed a Escalade fan blade that has 11 blades. I think it's overkill now. So I'm going to install a stock fan blade. The 4.0l in the wj jeep is very disappointing cause its supposedly a reliable engine but by them installing a electrical fan and putting the catalytic converters so high up and close to the engine doesn't help with keeping it cool. Bad design on the later model jeep. The older ones are the way to go. If I would of known what I know now. I would of got a 04 v8 HO overland but I've invested too much in mine i can't get what I put into this one so I guess I'm stuck with this junk till she dies again. I hope this helps bring some closure on that vehicle. I know how much you care about quality repair. As do I.
I agree on cleaning out the holes but that oil will never cause the bolt to stop from getting tight oil will simply get squeezed out because automotive threads are not air or liquid tight.
I have Jeep the exact year and trim as the model you're working on in this video. Mine has 215,600+ miles on it and the vehicle can't go past 70 mph without it feeling like something is yanking it back. Brand New transmission suspension, front end, rear end all looked at. Can You give me a quick guess on whats gonna go next or if its time to get a new vehicle?
Jimmie Givens timing chain brother they stretch and your Mechanic should have warned you at 150k
Kenny Barabino Thankyou because paying for them to find the problem would have killed me...
The lifters are bad the sound is significantly higher pitched. The lifter collapses internally. Put a quart of transmission fluid in it let it run 30 minutes at idle then change the oil. Many times carbon can get stuck inside the lifter.
1 minute in, I'm thinking valve clearances - noisy tappet. 20 minutes in I'm thinking check them. 25 minutes in, I'm thinking Eric will not be defeated. 30 minutes in, I'm in despair and about to give a thumbs down. Then I read the description for the video - 2001 car, long mileage, not worth the cost in labour to further investigate. Thumbs up! Great video and explanation. Hope you find out what did for it. We can only guess until you dissect it - if you can find it again. Great entertainment!
Eric, I wish I had seen your video two days ago! I did my 2000 GC 4.0 valve cover gasket yesterday after watching other videos and reading about it for a couple of months. The problem is all the info I collected wasn't for the GC WJ model. The other videos didn't have the resonator (down-stream from the cleaner), heat shield or that cable trough, plus they didn't show a GC with the last 4 bolt/studs under the windshield.
Some questions, how long would you say it takes to do just the valve cover gasket change (minus the tick diagnosis)? I got most of the bolt/stud out in maybe 30 minutes, but that last one on the driver side took another 30 minutes.
85inch/lbs = ~7ft/lb (just divide in/# by 12) and most torque wrenches don't go down to 7ft/# so how did you get the right torque for the cover? (I just guessed that pulling this hard at 11" is like lifting a bit less than gallon of water (8.331#).
What pattern did you follow when tightening (to 85in/#)? The service manual only shows 14 bolts/studs, but mine had 15. (I still kept the basic pattern moving clockwise starting with the center one on the passenger side.)
You used the Fel-Pro gasket and one of the 15 rubber grommets is different. Where does it go? (I'd think maybe the grounding strap stud, but wouldn't that help to isolate the ground making it less grounded? Maybe the coolant hose?
Any idea why so many studs? Only 3 of ?8 (I lost count) seem to be used on mine (coolant hoses, ground and cable in the back passenger side).
You said the bolt on the resonator was a 10mm... but what is the thread count and bolt size? Mine was missing so I'd like to replace it, and the bolts/studs from the valve cover are too big. By the way, the VC bolts/studs are a 1/4-20 into the valve cover body. I even measured them with a thread gauge. Metric my (*&)*(!% The nuts are 11mm, but I found the next closed SAE (7/16) fit tighter.
I enjoyed confirming that you and I both took off the resonator to get it out of the way and to detach the VC line from the manifold. I could not get it off the VC end and didn't want to break the plastic. I already split the other line into the resonator at the VC end. (Thank God for silicone "repair" tape until I get a new one.)
Been mentioned many times but that does sound like rod knock, although I have not heard it coming from that specific engine. Engine sounds like this resonate it makes is really hard to find the source. But usually if you can't find the specific location, it is from the engines internals.
Hopefully at some point we'll find out what the problem is, another excellent video as usual although I think your A/C vid was your best so far.
My 99 Jeep cherokee 4.0 has the exact same noise.
I thought possible flex plate bolts- they were fine.
I noticed when I changed the oil the oil felt very gritty.
Did a compression test and all pistons were within normal spec although #6 was at low end of spec.
Vacuum gauge held fine .
Took off oil pan and found chunks of piston skirt in the pan from #6 piston.
The rings had worn as a result and scored the cylinder wall a bit.
The engine had 290,000 miles so I’m gonna yank it and do a stock rebuild.
my 04 jeep sounds like there is a hundred of hammers under the hood until it warms up a little... lol
99 to 02/04 The perviously bulletproof 4.0L was turned into CRAP. They changed the castings on the pistons, and the head. The Piston skirts tend to crack off and shortly there after it blows up... There is a defect in the head castings I think between cyl 5-6 and it will weep coolant into the valve area. Usually slow enough that you may not see a color change in the oil, but it will mysteriously loose coolant.
The 4.7 V8 has issues too... mostly dropping the Steel valve seats out of the aluminum heads if they thing overheats even just a little. 93-98 had more robust engines.
The oil port for the lifer is plugged. They all do that for some reason. My guess is a hot spot in the oil port. Pull noisy lifter out, start motor for a few seconds enough to blow oil . Put lifter back in and it's fixed.
it is one of 2 things the jeep 4.0 is known for... 1 a rod bearing is to warn. you will still have decent oil pressure, just the knock like this one has. 2. a broke piston/piston skirt. it will also make noise like this.. just went through option one with my 96 jeep 4x4 4.0 i lucked out. pulled the oil pan and replaced all the rod bearings. problem is now fixed and runs like new.
hey eric, I have this noise that is definitely in time with the valve assembly. the odd thing is that it comes and goes. does this seem likely? in my experience with motor internals, once they go, they go. what do you think? pull the valve cover and take a peak?
If the problem is a sticky lifter it might be marginal and sometimes the lifter sticks, sometimes it doesn't. Do you know the history of the car? If it hasn't had its oil changed like it should have been you might give it some extra oil changes... say once every thousand miles or so for a while and see if the problem clears up.
I just had this happen. #3 piston skirt broke apart. It still had good power because it still sealed, but was sloppy in its motion. The skirt pieces were found in the bottom of the oil pan.
The seated harness assembly is what got me. It looks as if the bracket that holds that in place is bolted onto the fasteners.. and the only way to remove them is to break them. Ill have to take another look at it. Good idea using the 45* pliers.
I changed the head gasket on one of them last year. Took me 45 minutes to remove the cylinder head. A little longer to put engine back together . Very easy!!
My 04 does the same exact thing at start up, it's been like that for almost 2 years. 108,000 miles and still running strong. No other issues at all. I'm afraid of a broken piston; then again, so far I haven't heard of anyone having a catastrophic failure. That's one dependable little engine.
These engines are junk 108,000 miles should not be making a noise at all
@@Redheadedwizard what year is it ?
So you did fix or diagnose anything. Impressive....
Awesome video =D My 01 4.0 Jeep Grand Cherokee was doing the same thing and I figured it was the lifters. Now it's gotten to the point that when I turn it on, its super load and may have damaged something else internally. The engine has 198,000 and just replaced the tans about a 2yrs ago. So when this happened I said I had had enough and wasn't going to rebuild the engine. Now its just sitting in the backyard and I decided to buy a 2012 Toyota Prius C, which 51mpg versus 16 with the Jeep.
GAH! This is just like the Diary of Ann Frank. It ends abruptly and its all bad news. Well it was good seeing the removal of the valve cover. I have a 98 Grand Cherokee and sure would love more videos on dem Grand Cherokees.
That paper clip trick was spectacular!
Pull the oil pan. Simple job on that model and engine. You can then check for rod play and inspect the pistons. I would agree and checked the top end on the last 4.0 with a noise like that hoping for the best, but it sounds lower. The last one was a broken piston skirt and it seems common. Threw a set of new pistons in it without even pulling the engine. I thought the paper clip might be a good idea until you struggled to get some out. .. they make a universal rocker arm cover set that clips on to block the oil. I had a set at one time, but no idea where it went. I guess its been 10 years since I thought I might need it .lol
I need to do the valve cover gasket on my 1999 Jeep Cherokee and this was very helpful. Thank you!
Dear Eric, this noise might be a cracked or loose torque converter plate (flex plate) . Other possibility try listening to the noise from the oil pan, as it might be a rod knock which may require bottom end bearing. John Kaplanian
Eric, I have a 1998 4.0 (212k) and have the exact same sound (at all RPMs). If I backed off the torque on the rocker on 2nd rocker from the front, the sound went away completely. Performed a full top end job with new lifters (oil soaked before install), push rods, resurfaced the head, compression checked, all good, all back together. SAME SOUND! Sound is coming from the lifter just as it was before head job (stethoscope to find the sound) so my theory is it's a worn cam lobe and the lifter is slamming down creating the sound. With out pulling and replacing the cam, how can I run the engine as is, with less torque on the rocker bolt to alleviate the sound?
My gress is the spring in side the lifter is longer because you loosened up the rocker nut. The spring may be longer allowing less slop
Spring may have a weak point not allowing the strength to pushing the lifter on lob hard.so it's possible when you loosened the spring can now again push in a different spot on each coil of the spring.could be sticky lifter.run marvel mistory oil a new oil then loosen the rest like you did .if possible put back where nut was.my 2000.cherokee 4.0 has a lifter that makes a little noise .but after 2 mins it go away.4.0 s like zink .shell.oil I roseshella I think number 5 there a vedio.erric s cousin did one.the guy w beard.im tired .lol
eric, the fast way to isolate a noise to a cylinder would be revving the engine of idle, disable spark one by one until the noise goes away. So when the noise goes away after disabling say the cylinder two; then you know it that cylinder. Then from there is just a matter of top or bottom apart of the engine.
Can't do that with this particular setup, as the coils are all shared by one common rail.
My jeep makes a nasty knocking nose when you first start it up then it goes away, its been that way for 2 years, little beast still wont die :)
I have a 1997 with the same noise.
look up timing adjustments.
I had to realign my timing marks, and set first piston at TDC.
Then I removed distributor, and realigned it to the correct setting.
my engine was off by 5° and the plugs needed to be gapped properly.
Noise is gone, been like that for a year now.
runs like a champ.
How could he do that? these later ones don't have a distributor...
I almost acquired a 2000 GMC Yukon Denali ala 5.7 vortec V8 about a year and a half ago, with about 250k miles, that made a similar noise. My father in law and I argued over what the source could be, he said "rod knock" while I suspected loud lifter tick. Turned out to be a spun bearing making the noise. Supposedly whatever "technician" that worked on it before, forgot to put oil back in the engine before starting it up which is what caused it. And yes, I passed on the vehicle.
Bought (cheap) a 2001 Cherokee with that noise. Engine ran fine. Dropped the oil pan and #4 piston had broken skirt. Also found casting material in engine when replacing freeze plugs when engine was out.
I have a 2001 just like this one and it started with a slight ticking sound and then got worst, sounded just like this one. Finally the motor locked up, these 4.0l engines are notorious for cracked piston skirts due to design flaws. I bet if you drop the oil pan you would find pieces of a piston. Mine had a broken rod and piston skirt with another one that was cracked.