3.6 Cam Self destruction

[Mav4x4Chris]

If this were true, my wife would need a new engine every few months.
It absolutely makes no sense. It's internet lore, IMO, urban legend if you will.
It would require you to drive it that way constantly, every trip, all the time.
Sounds like those AMC folks who insist an oil bypass line is needed to keep oil to the rear mains - a guy did testing on a dyno proving them wrong, measuring oil pressure and flow through multiple spots in the engine, and yet the believers in the oil bypass line persist, the testing meant nothing.

Speaking on oil pressure, after reading this thread the other day I left my center screen on oil pressure and watched during a 35 mile drive with lots of stops and turns (back roads)- and assuming this gauge is reasonably accurate and not just generated by algorithm, the oil pressure in the 3.6L ramps up quick any time you approach 3,000 RPM. It was always 30 PSI or more at idle, and past 2,500 RPM is began to climb quickly, usually in the 60+ pound range by 3,000 and then shortly after topping at 78-82. It's certainly generating all the pressure it needs, at least.

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[seven30]

I realize there have been an increasing amount of these cam-related posts circulating the forums and FB groups. I am starting this thread to share my experiences and insights from the many posts I have been following.

I started experiencing the misfire issues at around 24k miles on a 2020 with a build date of Sept 2019. I swapped the cams and solenoids and after about ~5k miles, I have the same symptoms on Bank 1 with tick and misfire code. I have not pulled the valve cover but the symptoms are unmistakable from the first round (I have misdiagnosed things before )

I believe there is an issue with the oil channels in the head that get progressively worse over time preventing the necessary pressure to activate low-lift condition.

The rest of this post contains my findings from the 1st swap. I am now trying to decide if I swap the heads or throw in a long block. Alternatively, I am also considering just taking it to the dealer for diagnosis but I have never had a good experience, coupled with my supercharger is a risky proposition. I have decided to fix this right and then sell the truck. I love the supercharger torque but done with 3.6 foolishness. I think I am going with the diesel, yes I know I may be trading one devil for another.

I will continue to update this thread as I venture deeper into the situation.


I swapped the cams and found the bank 1 lobes to be consistently ground whereas bank 2 was more erratic.

There has been some assessments that Jeep installed the exhaust lash adjusters on the intake cams. Based on my tear down, this is not the case. The lash adjuster part numbers have been updated to a new rev and look different than the old adjusters. But there is no way the exhaust lash adjusters would work on the intake side. The height is just too different. The exhaust adjusters also have no oil paths whereas the intake does.

Lash adjuster photo:

The following is an approximation of the wear by lobe:

Bank 1:
Controlled by front solenoid

Cylinder 1 V1: 2.0 mm​

Cylinder 1 V2: 1.6 mm​

Controlled by rear solenoid

Cylinder 3 V1: 1.7 mm​

Cylinder 3 V2: 2.0 mm​

Cylinder 5 V1: 1.9 mm​

Cylinder 5 V2: 1.9 mm​

Bank 2:
Controlled by front solenoid

Cylinder 2 V1: 2.0 mm​

Cylinder 2 V2: 0.06 mm​

Controlled by rear solenoid

Cylinder 4 V1: 0 mm​

Cylinder 4 V2: 0.12 mm​

Cylinder 6 V1: 1.4 mm​

Cylinder 6 V2: 1.6 mm​

Bank 1 Intake Cam

Bank 2 Intake Cam

Would you tell us what brand and weight of oil your using to help complete the picture.

 

[BearFootSam]

Speaking on oil pressure, after reading this thread the other day I left my center screen on oil pressure and watched during a 35 mile drive with lots of stops and turns (back roads)- and assuming this gauge is reasonably accurate and not just generated by algorithm, the oil pressure in the 3.6L ramps up quick any time you approach 3,000 RPM. It was always 30 PSI or more at idle, and past 2,500 RPM is began to climb quickly, usually in the 60+ pound range by 3,000 and then shortly after topping at 78-82. It's certainly generating all the pressure it needs, at least.

What you are seeing is the dual stage oil pump. The ECM controls the pump output according to load and RPM. It seems like 3k is the switchover point during normal operation from low to high pressure output. This reduces parasitic load on the engine during low output conditions while still providing higher oil pressure when needed. I believe that this along with the ECM controlled alternator output and electro-hydraulic steering helps manage start up load during ESS. Rather than the old style of constant belt driven full load accessories, by disengaging or reducing output when unneeded, the starter has substantially less resistance to overcome during re-start. A further side effect is an improvement in fuel economy. It is really quite impressive that a naturally aspirated and port injected engine driving a 5,200lb lifted brick on ATs can return relatively outstanding fuel economy (23-24mpg) on the highway.

 

[DC3]

Would you tell us what brand and weight of oil your using to help complete the picture.

factory spec... 0w20. Mobil 1 full synthetic

For the first couple oil changes ~12k miles, I took it to the dealer (wave). After the dealer, I used 5w30 until the first cam episode ~15k miles and then used 0w20 afterwards.

OIl changes at 6k intervals through dealer and 5k on my dime

 

[DAVECS2]

I ended up having to change both cams. It happens on both sides, just seems to happen on drinkers side first. DC I think you are right the lifter design has been updated, but still a drastic update. To boot I did not tear down my exhaust cam because my ride needed to be back in action asap, it was my DD.

The test will not run because it was built for the circuit to have an oil pressure sensor that is not there. There's no way for the the ecm to know rockers are in high lift mode or not, and that's the problem.

You vcn start loosing VE on a cylinder pretty significantly and the first diagnostic you will see is misfire.

The 3.6 has really disappointed me in some serious ways. It took something that could of been really fun and I spend my days doing bar puzzles under the gun.

To boot Jeep has about 20 different ways they have tried to operate this engine and that in itself causes mass.confusion and heartache.

I troubleshoot very little supercharger install stuff. Most of it is factory issues that come to a head under forced induction.

If you are going to solve this problem, I think the fastest rout is to work with a cam and rocker supplier. WEBB cams is waiting for me to send them my take outs.

Run 5-30 it seems to help and does not adversely affect the phazers.

I'm you could get an oil pressure sender on the circuit that would tell you tons.

 

[Beat Army]

Soooo….trade these things in at the end of the powertrain warranty? Not much of a value proposition but likely a better deal than funding an engine tear down or swap.

 

[DC3]

I ended up having to change both cams. It happens on both sides, just seems to happen on drinkers side first. DC I think you are right the lifter design has been updated, but still a drastic update. To boot I did not tear down my exhaust cam because my ride needed to be back in action asap, it was my DD.

The test will not run because it was built for the circuit to have an oil pressure sensor that is not there. There's no way for the the ecm to know rockers are in high lift mode or not, and that's the problem.

You vcn start loosing VE on a cylinder pretty significantly and the first diagnostic you will see is misfire.

The 3.6 has really disappointed me in some serious ways. It took something that could of been really fun and I spend my days doing bar puzzles under the gun.

To boot Jeep has about 20 different ways they have tried to operate this engine and that in itself causes mass.confusion and heartache.

I troubleshoot very little supercharger install stuff. Most of it is factory issues that come to a head under forced induction.

If you are going to solve this problem, I think the fastest rout is to work with a cam and rocker supplier. WEBB cams is waiting for me to send them my take outs.

Run 5-30 it seems to help and does not adversely affect the phazers.

I'm you could get an oil pressure sender on the circuit that would tell you tons.

Well I dropped mine off at the dealer this morning, supercharger installed and all. I showed them the cams I replaced and explained the situation. The engine was ticking like crazy and with a regular misfire. I felt bad for my new cats .

I have no idea what to expect, but it is worth a try to get it repaired under warranty, I am sure I will need to recite the Magnuson Moss act, for whatever that's worth.

Worst case scenario, I replace the motor, myself.

@DAVECS2, I am sure they will try or will apply the TSB flash if they do the repair, I may humbly ask for your support.

I have already replaced the 3.6 with a 3.0JT. The diesel is a torque monster but Dave's tune on the 3.6 is magic. It's a shame to have factory shortcomings disrupt what would otherwise be a solid supercharged powertrain.

 

[DAVECS2]

The flash just moves the VVL activation point and dumbs down the knock sensors. You will need the supercharger tune to drive it

 

[Addisonjeep]

2022 Rubicon brought to dealer with a ticking. Jeep is now replacing the engine due to a wiped lube in cylinder #1 and metal in the oil.

 

[DC3]

The flash just moves the VVL activation point and dumbs down the knock sensors. You will need the supercharger tune to drive it

Thanks Dave! I have not been able to find the programming changes with the TSB.

No doubt on the supercharger tune. If the dealer pushed for the TSB, I figured I would be present, download the updated factory tune and "compile" that with one of your open tunes. Is that a bad idea? I assume the Jeep shouldn't even be started with factory tune, is this right?

 

[DC3]

Update: I dropped the Jeep off at the dealer and they called to say no ticking...... I was like, what the #$@#? I drove there and started the engine with the Tech present and sure enough it was ticking. I shared the factory cams and explained the wear patterns and mileage oddity. They agreed to take it under the knife, recognizing the issue is not related to the supercharger. Having the cams and rockers was critical for the conversation.

The case is being initiated as a warranty issue but it will depend on what they find and the extensiveness of the repair as to how it will ultimately be handled. I think I got lucky with how it's played out so far.....fingers crossed!

 

[DC3]

2022 Rubicon brought to dealer with a ticking. Jeep is now replacing the engine due to a wiped lube in cylinder #1 and metal in the oil.

How many miles on your '22?

I am puzzled by the inconsistency in mileage and model year.... this seems like either a quality issue or a combination of poor design (too close to the limits) and manufacturing variance....

 

[Hootbro]

factory spec... 0w20. Mobil 1 full synthetic

For the first couple oil changes ~12k miles, I took it to the dealer (wave). After the dealer, I used 5w30 until the first cam episode ~15k miles and then used 0w20 afterwards.

OIl changes at 6k intervals through dealer and 5k on my dime

Curious, what about using the 5W-30 oil made you discontinue it and go back to 0W-20?

 

[DAVECS2]

Thanks Dave! I have not been able to find the programming changes with the TSB.

No doubt on the supercharger tune. If the dealer pushed for the TSB, I figured I would be present, download the updated factory tune and "compile" that with one of your open tunes. Is that a bad idea? I assume the Jeep shouldn't even be started with factory tune, is this right?

If you let me know when your doing it, I will rebuild it asap while your there

 

[Addisonjeep]

~16,000 miles on my 2022

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