3.6 pentastar jku 2015 engine 140k miles

[OVERKILL]

I guess this is why Detroit Diesel didn't go with roller bearings in their series 53, 71 and 92 engines. Reliability.

I remember reading an article, many years ago, when roller rockers were becoming popular in HO race engines. They discussed the use of roller bearings versus bushings in rockers and followers. They were also referencing their use in passenger vehicles when the use of roller followers were becoming popular. Their conclusion was for longevity, roller bearings should NEVER be deployed. Roller bearings are very sensitive to their environment. Namely the condition of the oil they run in.

I realize the problems we are experiencing are more contributed to metallurgy and hardening and I cannot understand why manufacturers can't get it right since this isn't bleeding edge technology? But, I never understood the use of roller bearings for street use. Bragging rights?

I think the biggest insult is that we used to produce roller lifters in the 80's and 90's that were bulletproof. I re-used my OE 200,000 mile lifters on two different camshafts in my Mustang, they didn't bat an eye. They were made by Federal Mogul. The GM guys used to do the same thing.

At some point in the 2000's, QC jumped the shark, likely due to offshoring, and now properly manufacturing roller lifters and roller followers is mythical voodoo that we can't get right.

 

[ka9mnx]

The article also went on that for the slight decrease in friction, roller bearings were not worth the risk's!

 

[OVERKILL]

The article also went on that for the slight decrease in friction, roller bearings were not worth the risk's!

Well, the Modulars seemed to do just fine with their 90's designed roller followers I appreciate that a diesel is a different environment however.

 

[ARCOgraphite]

Those Chrysler 3.6 camshafts are some of the ugliest camshafts on the face of the earth. Just putrid.

Looks typical. you only machine what requires machining, the remainder is as-cast.
Here is a detail of one used cam pulled from a Toyota 2AZFE 2.4L from a Scion TC with 88k miles.

 

[TomYoung]

Has anyone offered an explanation of why this unusual wear occurred? I would be inclined to drive around on the new cams, change the oil, and see how it goes. The bottom end is probably perfect.

 

[ARCOgraphite]

The article also went on that for the slight decrease in friction, roller bearings were not worth the risk's!

Most designs went to stationary HLA with roller rockers when going from 30 to 20 grade oil. This is a disadvantaged 3rd class lever. Maybe two drivers here: Didn't pass the seq IVA or B cam wear test and excessive engine racket with SUB DOHC and solid tappets.

Funny they mention tappets in the r.o.; this engine does not use tappets.

 

[ka9mnx]

Well, the Modulars seemed to do just fine with their 90's designed roller followers I appreciate that a diesel is a different environment however.

The article wasn't speaking for Diesel engines.

Both my Dodge (3.9L) and Ranger (3.0L) have roller followers. Neither have roller bearings. Maybe some folks are confusing me talking about roller followers and not, the problem child, roller bearings in the followers and lifters.

 

[OVERKILL]

The article wasn't speaking for Diesel engines.

I was speaking to your reference to Detroit Diesel earlier.

Both my Dodge (3.9L) and Ranger (3.0L) have roller followers. Neither have roller bearings. Maybe some folks are confusing me talking about roller followers and not, the problem child, roller bearings in the followers and lifters.

Right, but the roller lifters I mentioned earlier have roller bearings in them, as do I believe the Modular roller followers (can't find an exploded view of one unfortunately).

IIRC, the Cummins N14 engine, which has been known for roller follower and camshaft issues, also uses roller bearings.

 

[goingplacesanddoingstuff]

No surprises here.

 

[ka9mnx]

I was speaking to your reference to Detroit Diesel earlier.

Right, but the roller lifters I mentioned earlier have roller bearings in them, as do I believe the Modular roller followers (can't find an exploded view of one unfortunately).

IIRC, the Cummins N14 engine, which has been known for roller follower and camshaft issues, also uses roller bearings.

The Cummins engines I was referring to were the BT's (Dodge). I'm not current with Modern OTR truck engines. It's been 30 years since I laid a wrench on them.

I remember putting rebuild kits in the DD followers. Punch out the center pin (bearing) and remove the roller. Drive the new pin through the housing and new roller then splade the pin to the housing. We re bushed the rocker arms too and replaced and spladed the end pin to the push rod. Great fun days!

 

[octank]

New pics

 

[ejes]

I had a 2015 Jeep Cherokee with the 3.2 variant of that engine. Never had any internal engine trouble, but I changed the oil every 5k and it ran very smooth and strong until I got rid of the thing last April at 100k.

At 75k, that car turned into a real nightmare POS. Transfer case went out and even though there was a service bulletin for replacement for that very part number, they wouldn't cover it because it was not hooked into the specific 4WD variant we had. The plastic oil filter housing warped and started leaking, had to replace the battery current sensor 3 times, shifter control went out and had to replace, transmission never did shift correctly and had a clunk at 40 mph when going uphill (had it re-flashed 5 times), on and on...

 

[Soft Cars]

Looks typical. you only machine what requires machining, the remainder is as-cast.
Here is a detail of one used cam pulled from a Toyota 2AZFE 2.4L from a Scion TC with 88k miles.

View attachment 183063

Here's one for a 1986 Ford Mustang 5.0L

 

[ARCOgraphite]

New pics

Need pics of the worn rockers that killed the cam.

Wonder if you had any collapsed hydraulic lash adjusters too? That would hammer the roller to death.

 

[ARCOgraphite]

Need pics of the worn rockers that killed the cam.

Wonder if you had any collapsed hydraulic lash adjusters too? That would hammer the roller to death.

View attachment 183561

I guess not.

 

[octank]

Update ! Jeep dropped the oil pan and found metal shavings and a piece of metal in the pan and have now submitted for an engine replacement. Lifetime warranty payed off big time with this

 

[nicholas]

Update ! Jeep dropped the oil pan and found metal shavings and a piece of metal in the pan and have now submitted for an engine replacement. Lifetime warranty payed off big time with this

Phew

 

[octank]

Does anyone know the part number for a new 3.6 pentastar engine crate from mopar ? Not the remanufactured or refurbished but actual brand new. Thanks

 

[Skippy722]

Does anyone know the part number for a new 3.6 pentastar engine crate from mopar ? Not the remanufactured or refurbished but actual brand new. Thanks

I didn’t see one specific for the JKU, but I found this one which says it fits 2020+ grand Cherokee/Durango. I wouldn’t see why it couldn’t work, unless they did something crazy with the bell housing.

2020-2022 Mopar Complete Engine 68233205AG | EastcoastMoparts

2020-2022 Mopar part # 68233205AG - Complete Engine

www.eastcoastmoparts.com

 

[octank]

I didn’t see one specific for the JKU, but I found this one which says it fits 2020+ grand Cherokee/Durango. I wouldn’t see why it couldn’t work, unless they did something crazy with the bell housing.

2020-2022 Mopar Complete Engine 68233205AG | EastcoastMoparts

2020-2022 Mopar part # 68233205AG - Complete Engine

www.eastcoastmoparts.com

Thanks