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if it is rod or main bearings then it gets worse under load. If it is an automatic you can hold the brakes in Drive and apply throttle. The knock will get worse. A manual you can push against a tree or something. If this goes away when the belt is off, a 2011 is still a 3.8, removing the belt doesn't spin the alternator, steering pump and A/C compressor. That's pretty solid sign it is one of those, these accessories aren't going to change a rod knocking. If you run max A/C does it change? If you turn the wheels left and right does it change? With the belt off do any of these three have any play at all? Can you move one of them up and down or in and out? They should spin freely and without any little "catch" or knock. A bad steering pump tends to "wine" not knock. An alternator can knock if the stators go bad. The A/C pump has a clutch and is the most likely accessory to "knock". If it is a manual, does it do it with the clutch pedal down? Wrangler clutches tend to have knock sounds at idle when the throw out bearing starts to go bad but again, removing the belt and the sound goes away it is almost certainly 1. the A/C compressor, 2. the alternator, or 3. power steering pump.

@ntaubitz You, sir, are a gentleman and a scholar! It's a manual. Didn't get worse or even noticeable under load, its basically just at idle, and if i raise the RPMs above around 1200, by 1500 the sound is gone. Max AC doesn't change it, neither does turning the wheels. It makes the noise with the clutch in or out, and in gear or neutral. It's a rhythmic chug/pulse/knocking and seems to be around the passenger side, and lower in the engine, which is why it seemed odd that removing the belt made it go away. I'm trying to chase this down, new-to-me 2011 Wrangler, took it to a "Jeep shop" (who said they hate 3.8s, AFTER they did the work) for baseline fluids, plugs, etc and they pointed out the noise. They said definitely piston slap or wrist pin, start the process to replace the engine under your 3 month warranty. That seemed extreme, since the thing runs great it's just making this noise. So, I took it to a trusted general mechanic who popped off the belt, and we noticed the sound disappeared. So, they replaced the tensioner and belt first, still made the noise by the time I got home, so they replaced the idler next. I noticed the sound got better but then returned after a couple days. I appreciate your insight! I can send you the video the first shop took, if you care to listen to it?

@@ntaubitz th-cam.com/video/JXMEY3rLwQc/w-d-xo.htmlfeature=shared

@ntaubitz And if I can also ask... removing the belt eliminates the noise, wouldn't it stand to reason that it would NOT be the a/c, alternator, or power steering? It should be one of the pulleys along the belt, no? And if the belt being off was a fluke, then I'm back to possibly rob bearing? Thanks! I posted the short video on my channel if you could take a look?

@@ntaubitz th-cam.com/video/JXMEY3rLwQc/w-d-xo.html&feature=shared

You put a wrench on the front of the engine on the balancer (front of crank). The connecting rods for broken caps is 20 ft/lb + 90degrees and for the forged it is 40 ft/lb + 90degrees

Are they broken caps (07-09)? Those only fit back together one way. If not, maybe they are marked somehow? Look for a stamp or marking that would be along the parting line. Next best would be to put the cap on the rod without bearings and make sure that cap fits perfectly on that rod.

Again, broken caps ONLY GO ONE WAY. When they are broken, the pattern is unique and the cap will only fit the rod. The rod is bored out and then broken in half.

At least 2 of the mains are cross bolted. I don't think you can do those unless you take the motor off the mounts and move it enough to get the bolts in and out. I do use spray cleaner to check oil paths, usually brake cleaner if there is a reason, like a spun bearing. If it is clogged I imagine it wouldn't last very long. I clean by putting Marv's Miracle in the oil for a bit before each change.

​@@ntaubitzappreciate you gettin bzck to ne on it man. Thanks.

These are cast rod caps. So they must match where they came off, right ? Problem is - someone moved them on me- I had them all set how they came out. 😢 So, yeah- since they aren't marked- this is gonna take some doin. Anything you can do about this ?

www.justanswer.com/jeep/80qyc-rebuilding-2007-jeep-3-8-v-6-need-torque-specifications.html

I used the existing bolts. Let me tell you, it took some serious doing to get that final torque number.

If you are referring to the adjustment collar with Allen key set screws, then that certainly shouldn't be that tight. Mine end up being just passed finger tight. If you are talking about the castle nuts, put some load on the knuckle first.

Hey Rob, Im having the same problem with mine. I was able to get them to tighten once, but they seem to loosen up so quickly, almost every 3 months... I went to check them again the other day and the wrench tool they provided just keeps slipping off because grease keeps getting in between the "adjustment nut" and the wrench acting as a lubricant... I can very clearly tell when they are going out of spec, my steering gets super soft and lots of play. Did you figure a solution out? Thanks

@@YamsYT im curious and this maybe a stupid answer as Im planning to get these too for my Jeep XJ, But would some sort of locktight be ok on that. put that Sh@!# on everything :D

That's the stupidest thing I've heard. Loctite expands, thus decreasing bearing clearances.

@@Void-gn9zm Because you have no clue why they do it...Maybe take a course in engine building...

That's what I do on every single engine I've built... Just for cheap insurance.

Because can for as such with tooths many much yes

I replaced rod and main bearings with the same size but not OEM manufacturer. At that time I bought from a higher quality manufacturer but I can't remember who.

@@ntaubitz is the rod bearings for the 3.8 v6 a size 0.25 ?? Is that standard size?

@@jayceeleon .025 is not standard.. Standard is just that..No numbers will be added.. And if you choose too do this. use the King Bearings..They will last..Think they are like $40.00 for set..

Thanks for this reply. I wondered the same thing.

Chrysler used two cast rods, a 4448904 in the earlier engines and 4654356 from ’01 through ’06. The 0015 powdered metal rod with the cracked cap was used from ’07 through ’09. www.enginebuildermag.com/2010/03/rebuilding-the-chrysler-3-3l3-8l-engine/

I got 2 of them. 2 are cross bolted and require getting the motor out of its mounts. The mains were fine. The rod bearings were worn as you see.

Btw mines not knocking im just seeing if this is common.

I change my oil, with Mobil1 synthetic every 2500 or so. My motor works hard and sees a lot of RPMs. It all depends upon what your motor goes through. This motor is notoriously dirty(oil) and in an offroad environment gets packed with mud often. If it doesn't get too hot and you keep slick oil in it, they should go basically for the life of the motor. Spun bearings tend to happen with dirty oil and high RPM. Stay out of the RPMs with dirty oil.

It could be simple and effective, or the crank is scored and a new bearing will just be junked immediately. I couldn't say without seeing what is causing the knocking and why. Remember the rod connects to the piston as well and although much less likely, it could be at the piston (pull the head). It really all depends upon what that crank looks like! My father did this exact same thing in his LeSabre and solved his knocking.

Cool. Thx. So what did your father do? Just replace a bearing or two? Mech says because this car sat for a year, maybe some thing gummed you and prevented oil from reaching that piston so maybe you’re right about the knocking coming from the top piston area. I baby the car and the knocking hasn’t gotten worse.

@@joephillips7612 Rod bearings were replaced. The parts are cheap, the labor expensive.

No need to remove heads. The rod bearings can be done without rolling. Those are easy once you get the pan off. The crank bearings must be rolled in and you can't get the cross bolted caps off of 2? Of them. Pull the motor to get all crank bearings.

@@ntaubitz I went back under and did your side to side motion. And up I most definitely have a few talking to me. Now I just need to figure out the size roller bearings and then I’m good..thanks for the great vid. Help tremendously

In this video? My black JK has 4.88 not sure about all the other rigs

4"

It's not a high performance engine. So no, there aren't easy options for different sizes. I used the higher quality (forget the brand) bearings and didn't measure the gaps. The rattles went away and it's been running fine for almost 2 years.

I have the 4.7 that started to knock and I saw there are several choices for bearing sizes. How do I know which ones to get

@@misterkota1252 get some plastigauge, measure the current gap, then get the right size over to bring it back into spec, or use a micrometer (but this is definitely not the best way, normally you’d have a machine shop check and true up the journals.)

No. This is Chrysler not GM/Buick but the same general technique would be used. They are both a V motor and the same bearing strategy is used basically in all motors. As long as the crank surfaces are good you can put new bearings in making sure the oil channels are aligned.

To be clear. Rolling in bearings is a technique when you don't want to remove the crank.

It is just a technique mostly for main bearings. I used a higher quality OEM fit replacement set of bearings for the rods and you don't need to roll them in because the rod can swing away after the cap is removed.

It doesn't lose or burn any oil. I'm not sure the miles but it's been doing great.

Is it still going I bought my 2 door jk in March 2007. Have 457 k on odometer. Had 2 back to back engine failures. Have thought about doing this

Well I sort of agree. Before purchase I contacted them and they said they are fine with RCV. They work great but I had to grind the head of a grease gun tip for clearance with the RCV boot.

I guess it depends upon your ability. It took me a bit longer shooting video. That sounds about right if I was just doing the job.

I did this on my BMW. Easy fix but dropping subframe and all other crap to get to it was a pain. Bearing replacement for 6, hour max

Ya, at one point I did the synergy high steer kit and at that time put all new rid ends in the steering. Mud in tires? Death wobble. Even with PSC big bore, death wobble. The TF ball joints have made the front end bad ass. The biggest difference with out a doubt.

@@ntaubitz Great!

It's all adjustable. Full traction lowers, replaced the heim with Johnny joints. Uppers are JKS. JKS track bars. Synergy high steer kit. Teraflex ball joints. PSC big bore box. It's been aligned and is within spec.

There's nothing stock in this jeep past the transmission except the brakes. It's all JKS, synergy, dynatrac, ARB, RCV, terraflex, tom woods etc. The front has been wonderful for probably 2 years now. The rear is stretched and the wheel base is 104". As of today I haven't had death wobble since the terraflex ball joints. It's going to 37s or 38s on this build so we'll see how built 44s hold up on a 2 door 2.8 at that wheel size.

Do it before it scores the crank! Happy wrenching.

I've had way too many engines, lol. Compared to the I6 this motor is not great for a Jeep, better for a minivan. I'm at 120k it's never hit the Rev limiter. Its always hesitated when cold. It has always rattled in the top end and now has some piston slap. It doesn't use or lose oil. It's changed every 1500 to 2500 because it dirties the oil so fast. I'm going to build a 3.8 and see if I can enjoy owning it.

I’m on motor number 3 at 116,000 miles and I check my oil religiously. These motors are shit. I hate the 3.8 with a passion. The caravan motor is not the exact same motor internally and it does have a long live span. Maybe that’s why you mechanic said that.