You apologize too much for being inexperienced, or not having the right this, or that--- just do your thing man, 99.9% of your audience appreciate you and respect your knowledge. Don't bring the whole vibe down for the 1 or 2 hate comments your expecting. :D **edit, actually, don't change at all-- everything you do and say is pretty endearing to your character, you're just overall a nice guy.
The Babbitt material is high silicone aluminum. It isn’t magnetic. It’s only the steel backing of the bearings that are attracted to a magnet. You’re got bearing failure somewhere to have glitter that big in the pan. Could be mains, or cam bearings but there’s a bearing dying somewhere in there.
Stop discrediting yourself. You’re a genius! most of us Shadetree mechanics just wonder why things do what they do and you take it a step further. you find out why things do what they do. Thank you for all your time you put into your videos.
Just sharing my experience with you after I saw your oil pressure/pump video. I never had low oil pressure issues, just general maintenance. The stock pump stayed at 40 and would drop slightly below when warm. I recently replaced my factory oil pump with a melling standard pressure pump. On top of that, I replaced the rear main seal, oil pan gasket, and the o rings in the filter adapter. Just using the dummy guage, it's noticeably higher when cold. Idles at 50-60 and will reach for 80 if above 2k rpm cold. At warm idle, it's just above 40psi. I look forward to your follow up video to find the cause. It's a super common problem, it'll definitely benefit people to have an answer.
Why strange ? The engine is worn out.. pressure is made on the rod bearings. I garuntee this engines beadings all show copper or worse. Only time an oil pump should be at fault for amc is if the gears wore grooves into the bottom plate like they do on amc 360s
Pumps do not make pressure, they create flow, restriction after the pump creates pressure, the main contributor of this restriction and creation of pressure is primarily the 2 types of bearings on the crank, which are the mains, and the rods, secondary to those is cam bearings, and then the upper end components in 3rd which have much less restriction. I noticed that you only changed the rod bearings and not the mains. I would start there.
Possible low oil pressure caused by cam shaft bearings? I used a Melling high volume pump and cross drilled the crankshaft. Don't forget to widen the holes in the new bearings when you install them. You can also drill the oil filter housing bolt out a little bit more.
One thing that might help you I have found to take parts cleaner, remove the pressure sensor take the little red hose, go into the sensor hole, put a rag around it, crank it up all the crap out of the hole do it again and see if that helps your pressure
Resistance to flow is the only way to build pressure. Pumps don’t make pressure they are positive displacement they pump as much as they pick up. I seen you plasti gauge one rod bearing, have you plasti gauged all the mains and all the rod bearings? Just curious as the initial pressure is developed during the flow to the mains. And as the engine warms up obviously the clearances get greater. Bleed off from a leaking galley plug could also cause a loss in pressure . If the oil bleeding off internally. The springs provided with the pumps only change the pressure at which the pressure relief valve opens. An 80 psi spring isn’t going to make 80 psi the relief just stops the filter from exploding basically lol. I wonder if you went to a thinner cold weight oil like 5w40 if you’d see a change just based on the volume change. I guess theoretically since 5w40 and 15w40 are the same viscosity at hot idle that won’t really make a difference. Maybe she’s just clapped out try 10w50 lol
I’m definitely wanting to know the cure. I’m in this same position with my XJ and I’ve actually messaged Dex and Justin looking for help. Hope you find the solution and appreciate this video.
When you have the pin off, take a look at the cam bearings. That's how I found the bad cam bearings online. You'll definitely seen squeezing out from the camp mind did the exact same thing
I bought an97 XJ from an old lady completely stock. They rarely drove it. Oil pressure after warm up was below 20. Drove it 500 miles and havent had an oil pressure problem since. Thought that was interesting good video Dex!
I've had a 90XJ it ran 40-45 at idle (warmed up to operating temp) pressure until I got talked into replacing the stock pump when I had rear main seal and oil pan gasket replaced. 35 miles later it failed trashed the engine. The replacement at best was 20-25 psi driving. I'm guessing it has more with wear of cam bearings and top end for oil pressure. BTW: I like your engine test stand. I need to build one i think. When I get my garage built.
4.0 liters do not like off the shelf high volume or high pressure oil pumps. They put too much pressure on the distributor/ cam sync gear. This causes them to wear prematurely, and the metal from the gears ends up wiping the lobes off number 3 and 4 cylinders on the cam. I figured this out the hard way but the guys at 505 performance straightened me out when I was building a lot of jeep strokers.
Another way to increase oil pressure is to take out the Carter pin. Tap the retainer cap ( whatever its called) that silver plug down a little where the return oil spring housing is. Place 1 to 2 thin washers in remaining space, return Carter pin. You will have an increase of 5 to 10 lbs. Old mechanics trick.
Try just using straight 30HD oil. That's what I use in my 93 Cherokee. It's diesel engine oil. I've got over 300,000 miles on it. I haven't done anything to the engine thats required removing oil pan or head. The oil pressure always stays 40 or higher. To be fair I bought the jeep used so I don't know it's whole history. I do notice that there's piston slap noise after it warms up good. Keep em coming.
Mine reads the same, however with a mechanical gauge fully warmed up HOT it’s 50 when on the throttle and 25 at hot idle. Even when my cluster says 45 driving / 10 idle.
My dad bought an 01 new and had below 10psi idling with very few miles. Changed pump/didn't help. I got the jeep years later and starting mudding with it. Always 40-50 cold and below 5 idling. Motor still ran after I scrapped the jeep due to unibody breaking in multiple spots
they make those oil filter relocation brackets to mount on top of the alternator mount bracket? Would be pretty sweet to have it right there for easy access.
@@Jasongross82 Naw, as far as I know all of the 4.0s have the filter where it is in this video. the AC compressor normally goes there. but its a jeep, ya know?
@@xSKOOBSx I read that wrong. I thought it said relocate the alternator up top. Like the tj does, the xj has a low mount alternator that ends up ender water allot
better pump test would have been to put a needle valve on the end of the hose near the round up bottle and a pressure gauge.. then on the first test open the valve until the pressure was 40 psi behind the valve and then see how long it took to pump the oil out. instead of 10 seconds it would have been a much longer and easier to measure time and also operating the pump closer to the pumps intended operation point on the pressure flow curve. but just find the problem in the engine.
My xj does the low oil pressure after it gets to temp with a new built motor also it broke a high flow so I threw a stock pump back in but still goes to about 30psi until under load
And I think on the oil filter hosing oring where you said if it was leaking it wouldn’t matter. Yes and no. I think it would have oil yes but sensor wouldn’t see the pressure but engine would.??
Great video I'm having some oil pressure issues on an 02 wj 4.0 so ya sounds like I got a lifter pecking at warmup just bought the jeep about to flush it out and change oil wish me luck lol
thanks for taking the time to do this tedious testing... really didn't learn much but the high flow looks like a winner.... but the real problem is in the engine. I am wondering why it drops so much when it gets warm?
opposite takeaway for me... all the pumps work. one had higher cold pressure but lost it more when hot... high flow would seem best... but the test really was only testing at low pressure on the flow curve.
I was told before if your main bearings are wore out you can have low oil pressure. Idk if you can test and check that? Plastic gage before and after a rebuild on the lower end?
Duhh . I am honestly shocked he thinks an oil pump will help.. unless there is scoring on the pumps plate it wont do anything. Low pressure is from lose tolerances on the crank journal and rod bearings.. thats engine 101
Off subject... can I trim a chunk off the fins of a NP 236 Tcase on my 99 blazer trailblazer? Torsion bar support is too close and the other crossmember doesn't move. HeLP!
Just from my own experence with low oil pressure. Be careful with China aftermarket pumps. Relief valve cracks open then sticks open. Cost me a newly rebuild engine with burnt cam lobes, lifters, and crank bearings all because I could not figure out root cause for minimal oil pressure.
What is that high pitch sound that it makes that first time you show it running? My engine makes that sound when I apply throttle while going along. Not when going hard but when feathering it as I just cruise along maintaining speed.
Yea ours with 430k miles sits at 30 hot idle.. and 40 load.. been like that for its entire life. This guys 4.0 is jist worn out. The rod bearings are bad or the journals
No. Amc specs are 10 per 1000 rpm. Amc 360s ran 15-20 factory at idle. All normal. If the psi doesnt go up when revved then you have a problem. But this 4.0 is simply worn out 10psi is too low.. rod bearings and journals are worn out. Thats engine 101 here.. low oil pressure from an oil pump on these mechanical pumps is only from scoring on the plate the gears sit on. Other than that the engine is worn out.. plain and simple. Dex should know this
Why dont you jist build the engine with new bearings.. oil pumps arent gonna solve low oil pressure on a 4.0, its not like its an amc 360... an anc 360 normal hot idle oil pressure is like 15-20 psi... load is 40-50. Thats normal per amc specs But our 4.0 with 430k miles is still at 30pai hot idle and 40 load. Like it was at 50k miles. Clearly that 4.0 youre working on is worn out. And tbh i feel youre wasting your time with oil pump shennanigans. Engine 101 oil pressure is created by bearing clearances... Only if the mechaincal oil pump plate is scored will it affect oil pressure.
One thing that might help you I have found to take parts cleaner, remove the pressure sensor take the little red hose, go into the sensor hole, put a rag around it, crank it up all the crap out of the hole do it again and see if that helps your pressure
You apologize too much for being inexperienced, or not having the right this, or that--- just do your thing man, 99.9% of your audience appreciate you and respect your knowledge. Don't bring the whole vibe down for the 1 or 2 hate comments your expecting. :D
**edit, actually, don't change at all-- everything you do and say is pretty endearing to your character, you're just overall a nice guy.
In engineering it takes awhile to teach new engineers not to do that: you are right, Dex, just talk without apologizing or explaining situation
I mean yall could just watch the video and not criticize the man for literally being himself
@@TrailswithChad standard crit 101, you have to stfu and git to your point: tuff love for the man -- I hope he hears it
i already edited my post, and changed my mind-- click the read more.. xD
@@TrailswithChad
@ab2230 so that's why engineers come off as pricks, they were conditioned to not apologize lol
The Babbitt material is high silicone aluminum. It isn’t magnetic. It’s only the steel backing of the bearings that are attracted to a magnet. You’re got bearing failure somewhere to have glitter that big in the pan. Could be mains, or cam bearings but there’s a bearing dying somewhere in there.
Stop discrediting yourself. You’re a genius!
most of us Shadetree mechanics just wonder why things do what they do and you take it a step further. you find out why things do what they do. Thank you for all your time you put into your videos.
Just sharing my experience with you after I saw your oil pressure/pump video. I never had low oil pressure issues, just general maintenance. The stock pump stayed at 40 and would drop slightly below when warm.
I recently replaced my factory oil pump with a melling standard pressure pump. On top of that, I replaced the rear main seal, oil pan gasket, and the o rings in the filter adapter. Just using the dummy guage, it's noticeably higher when cold. Idles at 50-60 and will reach for 80 if above 2k rpm cold. At warm idle, it's just above 40psi.
I look forward to your follow up video to find the cause. It's a super common problem, it'll definitely benefit people to have an answer.
Beyond strange that a pump made like NO tangible difference in this situation. Fantastic teachings as always Dex, Thank you!
Why strange ? The engine is worn out.. pressure is made on the rod bearings. I garuntee this engines beadings all show copper or worse.
Only time an oil pump should be at fault for amc is if the gears wore grooves into the bottom plate like they do on amc 360s
You have amazing patience
well you helped me. I was going to buy a rebuild kit and won't now
Pumps do not make pressure, they create flow, restriction after the pump creates pressure, the main contributor of this restriction and creation of pressure is primarily the 2 types of bearings on the crank, which are the mains, and the rods, secondary to those is cam bearings, and then the upper end components in 3rd which have much less restriction. I noticed that you only changed the rod bearings and not the mains. I would start there.
I got the Melling high volume pump and haven't had any issues with it. 2000 XJ with 284000+ miles on it. But now I have lifter tick.
Possible low oil pressure caused by cam shaft bearings? I used a Melling high volume pump and cross drilled the crankshaft. Don't forget to widen the holes in the new bearings when you install them. You can also drill the oil filter housing bolt out a little bit more.
Camshaft bushings will fix your low oil pressure issue
One thing that might help you I have found to take parts cleaner, remove the pressure sensor take the little red hose, go into the sensor hole, put a rag around it, crank it up all the crap out of the hole do it again and see if that helps your pressure
Resistance to flow is the only way to build pressure. Pumps don’t make pressure they are positive displacement they pump as much as they pick up. I seen you plasti gauge one rod bearing, have you plasti gauged all the mains and all the rod bearings? Just curious as the initial pressure is developed during the flow to the mains. And as the engine warms up obviously the clearances get greater. Bleed off from a leaking galley plug could also cause a loss in pressure . If the oil bleeding off internally. The springs provided with the pumps only change the pressure at which the pressure relief valve opens. An 80 psi spring isn’t going to make 80 psi the relief just stops the filter from exploding basically lol.
I wonder if you went to a thinner cold weight oil like 5w40 if you’d see a change just based on the volume change.
I guess theoretically since 5w40 and 15w40 are the same viscosity at hot idle that won’t really make a difference. Maybe she’s just clapped out try 10w50 lol
I’m definitely wanting to know the cure. I’m in this same position with my XJ and I’ve actually messaged Dex and Justin looking for help. Hope you find the solution and appreciate this video.
The crank and rods have priority oiling. Then cam and lifters.
Cool content thanks for taking us on a learning experience hope you show the rest of you fixing the motor I'm interested in what it is.
When you have the pin off, take a look at the cam bearings. That's how I found the bad cam bearings online. You'll definitely seen squeezing out from the camp mind did the exact same thing
I bought an97 XJ from an old lady completely stock. They rarely drove it. Oil pressure after warm up was below 20. Drove it 500 miles and havent had an oil pressure problem since. Thought that was interesting good video Dex!
Same on mine, mine is healthy, I run 15 psi hot
I've had a 90XJ it ran 40-45 at idle (warmed up to operating temp) pressure until I got talked into replacing the stock pump when I had rear main seal and oil pan gasket replaced. 35 miles later it failed trashed the engine. The replacement at best was 20-25 psi driving. I'm guessing it has more with wear of cam bearings and top end for oil pressure.
BTW: I like your engine test stand. I need to build one i think. When I get my garage built.
Why would anybody talk you into doing that with 40 to 45 psi at hot idle . That’s far better than most .
Shim the bypass spring
4.0 liters do not like off the shelf high volume or high pressure oil pumps. They put too much pressure on the distributor/ cam sync gear. This causes them to wear prematurely, and the metal from the gears ends up wiping the lobes off number 3 and 4 cylinders on the cam. I figured this out the hard way but the guys at 505 performance straightened me out when I was building a lot of jeep strokers.
Thanks for the information.
Great video. Can’t wait to really see what’s wrong with it
Favorite guy on TH-cam right there! Crazy as hell but smart!
Another way to increase oil pressure is to take out the Carter pin. Tap the retainer cap ( whatever its called) that silver plug down a little where the return oil spring housing is. Place 1 to 2 thin washers in remaining space, return Carter pin. You will have an increase of 5 to 10 lbs. Old mechanics trick.
I could be totally wrong but isn't the drill speed more equivalent to 3000 rpm or so because the cam is spinning slower than the crank?
Correct crank to cam ratio is 2:1
@@mkbassman222 thanks. I realized that afterword but may my theory still be true because it’s still faster?
Good video. Thanks for the pump comparisons.
Great video dex. Putting a HV in my red jeep did help.
Try just using straight 30HD oil. That's what I use in my 93 Cherokee. It's diesel engine oil. I've got over 300,000 miles on it. I haven't done anything to the engine thats required removing oil pan or head. The oil pressure always stays 40 or higher. To be fair I bought the jeep used so I don't know it's whole history. I do notice that there's piston slap noise after it warms up good. Keep em coming.
4:57 would a gasket out of a filter work....
Been threw this before. I done cam bearings rod bearings and mains. Still had 5 psi. I gave up and sold the damn thing.!!
I did too, and still driving it for last 10 years.
It prolly would have gone a couple hundred thousand like that …
I think that flow vs pressure is what counts.
Dex knows best.
Love this video, I run 45 psi cold and 15 hot driving around, 1998 gauge cluster oil pressure, Jeep runs healthy.
Mine reads the same, however with a mechanical gauge fully warmed up HOT it’s 50 when on the throttle and 25 at hot idle. Even when my cluster says 45 driving / 10 idle.
My dad bought an 01 new and had below 10psi idling with very few miles. Changed pump/didn't help. I got the jeep years later and starting mudding with it. Always 40-50 cold and below 5 idling. Motor still ran after I scrapped the jeep due to unibody breaking in multiple spots
Really helpful info, I own three manuals and none really say much about pressure. Super helpful. Appreciate it.
On my AMC 360 I use a thinner oil pump gasket and it raised the oil pressure slightly.
I always wanted to kno these answers bud. Good work.
Bearing clearances are too large?
Keep up the vids man!!! I would love to work on jeeps all day.
they make those oil filter relocation brackets to mount on top of the alternator mount bracket? Would be pretty sweet to have it right there for easy access.
Isn't that where the tj is located
@@Jasongross82 Naw, as far as I know all of the 4.0s have the filter where it is in this video. the AC compressor normally goes there. but its a jeep, ya know?
@@xSKOOBSx I read that wrong. I thought it said relocate the alternator up top. Like the tj does, the xj has a low mount alternator that ends up ender water allot
@@Jasongross82 oh I gotcha, yeah my yj has the alternator about as high as the air intake so it works out haha
better pump test would have been to put a needle valve on the end of the hose near the round up bottle and a pressure gauge.. then on the first test open the valve until the pressure was 40 psi behind the valve and then see how long it took to pump the oil out. instead of 10 seconds it would have been a much longer and easier to measure time and also operating the pump closer to the pumps intended operation point on the pressure flow curve. but just find the problem in the engine.
My xj does the low oil pressure after it gets to temp with a new built motor also it broke a high flow so I threw a stock pump back in but still goes to about 30psi until under load
And I think on the oil filter hosing oring where you said if it was leaking it wouldn’t matter. Yes and no. I think it would have oil yes but sensor wouldn’t see the pressure but engine would.??
Bottom of the line
10-15 psi hot idle is not low.
Vw beetle have 3-5psi at idle
And they’ve been driving around for almost a hundred years.
Its low trust me.. AMC specs call for no less than 15 at idle.. this engine is worn out.. 4.0s dont run at 10psi when healthy.
Mopar specs say that 10 psi per 1,000 rpm is adequate for the 4.0 motor .
@@Rancherinaz thats bare minimum.. not normal
Now that is interesting 🤔
Thanks for your time with this video ❤
Hit that like for Dex!
"I'm not a scientist" LOL!
Great video I'm having some oil pressure issues on an 02 wj 4.0 so ya sounds like I got a lifter pecking at warmup just bought the jeep about to flush it out and change oil wish me luck lol
thanks for taking the time to do this tedious testing... really didn't learn much but the high flow looks like a winner.... but the real problem is in the engine. I am wondering why it drops so much when it gets warm?
good job........ i agree with to many appoligies
Cam bearings
I strongly recommend you watch the oil geek junior lake speed?
Love the folks-eneering !
My yj isn’t very high anymore. I don’t drive it much anymore though. I’m really curious to find out what is going on inside this engine.
High volume is not the same at high pressure
Thank you for all the information!
great video, curious what’s causing such low oil psi.
Nice work, appreciate this video
I thought you were getting the best results with the high volume oil pump. Is that the conclusion of the testing you have done here.?
Thanks for all your effort in helping to enlighten us all. I guess the takeaway is that there's nothing wrong with that motor, and all oil pumps suck.
opposite takeaway for me... all the pumps work. one had higher cold pressure but lost it more when hot... high flow would seem best... but the test really was only testing at low pressure on the flow curve.
My 2 cents for what its worth its gonna be main bearings but great little video glad I stopped in 👍👍
Great info!
I was told before if your main bearings are wore out you can have low oil pressure. Idk if you can test and check that? Plastic gage before and after a rebuild on the lower end?
Duhh . I am honestly shocked he thinks an oil pump will help.. unless there is scoring on the pumps plate it wont do anything.
Low pressure is from lose tolerances on the crank journal and rod bearings.. thats engine 101
Does the Oil Weight make a Difference ?? I saw a video ( can't remember who) said use like Diesel engine oil like 15w40 ??? Keep um comin !
On mine xj I have no oil pressure it is the wiring I have changed oil pressure sending unit and have been driving for years
my ZJ runs 20 psi on the dot at operating temp except when im in the throttle
keep the vids coming thank u
The same results that I got while doing the same thing, always nice to get confirmation. Have you checked the end play on the mains?
Love this
Dax is my fav youtuber right now . Just doing shit himmself and a TAD bit help from the machinist friend. He doesnt fuck around
i had a jeep come in the shop same deal high volume pump no difference wound up he was using a Fram filter changed to Wix problem gone never came back
Did you do cam bearings? Might of missed it if you did? I know you did rod bearings. Crank ( watched more answered that one) and cam bearings?
Bravo
Mine gets only 1/4 way up the dial when its warm.. so watching this with some interest.
10 psi per 1,000 rpm is considered adequate for the 4.0 .
Can u do a wiring harness in the engine bay i have a 90 xj Laredo with no wires going to the temp gauge but runs great still
Have you checked main brg clearance
Off subject... can I trim a chunk off the fins of a NP 236 Tcase on my 99 blazer trailblazer? Torsion bar support is too close and the other crossmember doesn't move. HeLP!
Just from my own experence with low oil pressure. Be careful with China aftermarket pumps. Relief valve cracks open then sticks open. Cost me a newly rebuild engine with burnt cam lobes, lifters, and crank bearings all because I could not figure out root cause for minimal oil pressure.
What is that high pitch sound that it makes that first time you show it running? My engine makes that sound when I apply throttle while going along. Not when going hard but when feathering it as I just cruise along maintaining speed.
Belt slipping
Cam lifters and bearings is the issue I think.
Whats the part number for the oil adapter to the block?
What was the bore like for the pressure relief piston?
Higher volume doesn't increase pressure
I think my 4.0 sits at 40 basically all the time, regardless of temperature... unless it is off of course. only 160k miles and stock.
Yea ours with 430k miles sits at 30 hot idle.. and 40 load.. been like that for its entire life. This guys 4.0 is jist worn out. The rod bearings are bad or the journals
Cam bearings?
Where you located at Dex TN?
You could always send a oil sample to a lab. They'll tell you what in the sample
God bless
Ummm...
Thanks.
What’s your favorite oil for the 4.0!!!?
Like video
10 seconds between life and death wow. Well I guess that’s plenty of time before you get completely screwed no problem
5 psi per 1000 rpms is probably fine.
No. Amc specs are 10 per 1000 rpm. Amc 360s ran 15-20 factory at idle. All normal. If the psi doesnt go up when revved then you have a problem.
But this 4.0 is simply worn out 10psi is too low.. rod bearings and journals are worn out. Thats engine 101 here.. low oil pressure from an oil pump on these mechanical pumps is only from scoring on the plate the gears sit on.
Other than that the engine is worn out.. plain and simple. Dex should know this
🤘🏼😁🇺🇸
And why we doin this. For science 😳
Why dont you jist build the engine with new bearings.. oil pumps arent gonna solve low oil pressure on a 4.0, its not like its an amc 360... an anc 360 normal hot idle oil pressure is like 15-20 psi... load is 40-50. Thats normal per amc specs
But our 4.0 with 430k miles is still at 30pai hot idle and 40 load. Like it was at 50k miles.
Clearly that 4.0 youre working on is worn out. And tbh i feel youre wasting your time with oil pump shennanigans. Engine 101 oil pressure is created by bearing clearances...
Only if the mechaincal oil pump plate is scored will it affect oil pressure.
Maybe the phrase should be, rebuild your motor????
Good information!
Love your content Dex. Did they kick you off of Instagram? I've been trying to support and share your stuff wherever I can.
High volume is not high pressure.
One thing that might help you I have found to take parts cleaner, remove the pressure sensor take the little red hose, go into the sensor hole, put a rag around it, crank it up all the crap out of the hole do it again and see if that helps your pressure