Cam failure question/poll

[Stan H]

I found out Friday afternoon that the motor is shot. At 122,000 MI, with regular oil changes using full synthetic oil, this piece of crap has died. Lost compression in cylinder number four had coolant in three and five cylinders. This is it I'm done, and Chrysler will not stand behind it knowing that this is a common failure. I'll never own another one! And the kicker is Jasper Engines doesn't even have this motor in stock, I can only guess because there's so many of them have to be replaced!
Buyer beware folks that's all I can say.

Bye Bye Bubba

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[harryator]

2022 JT, around 24300 Miles, got a P0306, serviced by dealership as per TSB for cam/lifters replacement; took about 2 months due to delay in parts availability.

 

[piroman683]

welp, I am now replacing Right side Intake again. this is replacement #5. I installed the Magnuson SC at 60k miles. I also started racing the truck in Baja after the 3rd cam replacement. I picked mine up Oct. 30, 2020.

#1 - 58,000 - LH
#2 - 75,000 - RH + new long block (was told to order a new engine due to metal shaving risks, so I did)
#3 ~ 87,000 - LH
#4 ~ 102,000 - LH
#5 ~ 119,000 - RH

Starting with #4 I've done this myself, takes about 7-8 hours, but getting faster at it. I'm just sick of dealing with this issue.

In Baja, and in most offroad cases, I am driving high speeds, RPMs are usually 3000-4000 range.

 

[MyMojave]

If you guys look into the Variable Valve Lift system on these PUG 3.6 engines (2018 and newer) and look at its design and use, you’ll see why these could be having so many cam and lifter failures. At least, this is my take on it. Mind you I’ve probably done more research and study on this than the average Joe.

Almost every camshaft/lifter failure I have seen on these newer engines post 2018 is the center lobe (high lift) and not the two outer lobes (low lift). The two smaller outer lobes of the cam shaft are what are used 80 percent of the time the engine is running. Most of the damages on these newer engines are the big center lobe/high lift lobe.

The high lift side doesn’t use a traditional roller/rocker. It uses a pin and its engagement is a very abrupt event. Ironically, when I developed tuning on these I actually discovered that “high lift” mode isn’t even used for high power and that high lift is used more like a way to add airflow for emissions purposes at lower load. Think of the engagement points as being very similar to when Eco/MDS/V4 mode kicks in on the hemis and GM V8 engines. The people who have been saying for years high lift kicks in over 2800 RPM are straight up wrong.

I made a whole video about this debacle, and I am confident this hi lift system is partially causing premature cam wear, in addition to less than quality materials. It's activation points are odd.




This abrupt engagement can actually be felt if you feel for it closely while driving. It comes off as a misfire or stutter feeling. Usually around 1800-2200 RPM at lower load and slower acceleration. It can be felt at highway speeds too.

I’ve got a few threads on the JL forum that cover this and a few YouTube videos floating around too. The only fix at this time is having high lift VVL tuned out, which I do. But I can’t help but wonder if disabling the high lift side will help alleviate these failures.

You’ll probably never see a formal fix from Jeep in the USA for this because it will effect emissions and they won’t jump through the hoops for that.

So raw dog the heck out of the 3.6 and you may not experience cam failure? I got no problem with that.

 

[aquaflamz]

I have a question at the end of this...

My vehicle has just over 114K miles and this is what I found after pulling off the right cover. I could hear this underlying knock/tap sound which was easier to hear from inside the vehicle at some points. Also while driving, I would get this clacking noise periodically while under light acceleration. After watching bmpcamry's video, I think I now know what that loud clacking was. Haha
A few days before I opened up the valve cover, the engine made that loud clacking noise a lot worse than it had done previously. Just for a second or two...
I stopped driving it. Did my own oil change and inspected the oil filter. I could see very tiny glitter in the filter media. It was only the fwd valve on Cyl #1. All the other lobes looked just fine. Replaced the camshaft, all lash adjusters and rockers.

So, my question: I was researching about the lash adjusters for the intake rockers. I heard its best to not install them fully pumped up, but with a little give in them and let the engine finish priming them when I crank it before starting. If I remember correctly, two of the six had a little bit of give and the others felt firm. Any thoughts?

 

[LouisvEarlleJT]

I have a question at the end of this...

My vehicle has just over 114K miles and this is what I found after pulling off the right cover. I could hear this underlying knock/tap sound which was easier to hear from inside the vehicle at some points. Also while driving, I would get this clacking noise periodically while under light acceleration. After watching bmpcamry's video, I think I now know what that loud clacking was. Haha
A few days before I opened up the valve cover, the engine made that loud clacking noise a lot worse than it had done previously. Just for a second or two...
I stopped driving it. Did my own oil change and inspected the oil filter. I could see very tiny glitter in the filter media. It was only the fwd valve on Cyl #1. All the other lobes looked just fine. Replaced the camshaft, all lash adjusters and rockers.

So, my question: I was researching about the lash adjusters for the intake rockers. I heard its best to not install them fully pumped up, but with a little give in them and let the engine finish priming them when I crank it before starting. If I remember correctly, two of the six had a little bit of give and the others felt firm. Any thoughts?

Yeah, rockers are supposed to have a bit of wiggle to them (though wiggle isn't even the right word because that makes it sound loose). Not sure how wide spread that would be though across all engine assemblies.

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