OIL, 0-20 or otherwise (couldn't find the other oil threads)

[ShadowsPapa]

Like mentioned though, why not both banks if that was the case?

This only started recently - 2016-2019 were not problematic, then 2020 all heck broke loose, it's dwindled down from there (not gone, but in 2020, you had failures inside of 10 or 20K miles)

Right bank in almost all cases, 2020+ in almost all cases.

What changed.

Castings ? Faulty moldings ? Faulty head casting ?

Oil gallery restriction somewhere?
Heads don't interchange like in the old days, there's a left and a right.

I seem to also have a TSB, can't find it now, about lash adjusters causing noise but it was aimed at the left bank as I recall.
Really wish I could find that one.

but the only thing that ever made sense was the claim the RH side head was the last place to build oil pressure from sitting cold.

Not sure why that would matter since the oil pressure builds before the display can even keep up with that pump sitting in high volume mode during start-up.

If you saw the oiling system diagrams, oil galleries and so on, it should be the left bank or even bank if that was even possible. The right side is a bit closer to the main oil gallery.
Pressure can't build until all passages are filled anyway.

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[Hootbro]

There is no logic to it being a material defect on just one side unless there is a design issue unique to it the material does not account for.

 

[ShadowsPapa]

Whatever it is - it started in 2019 for the 2020 model year.
It wasn't a "thing" prior to the 2020 model year - and yet they are the same engine "design".
Location? Casting issues? Production issues?

We don't yet know how the 2024+ model years will be - if they don't have the problem, then the source of the issue was in Mexico.

Since the heads are very different, was there a post-casting process that wasn't taking care of something on the right side, but did on the left side?
Was there a problem with the castings themselves starting in 2019 (2020 model year)?

Something changed. The general engine design didn't change.
Same oiling system, same pump, same oil galleries.
If it was a design issue, it would have begun right out of the gate with the 2016 models.
Has it been a problem for 2016-2019 Grand Cherokees? Not according to Charles (nor any other information I've found to date)

 

[Hootbro]

Can find plenty of threads on the JL side of 2018 and 2019 3.6l right side valvetrains being eaten.

https://www.google.com/search?q=201...cam+replacement+site:www.jlwranglerforums.com

 

[Gatorac]

It would be interesting to know what oil (weight, brand) and what oil change interval was used for those with failures. I'd also be curious about the use of ESS on motors that had issues.

 

[ShadowsPapa]

Can find plenty of threads on the JL side of 2018 and 2019 3.6l right side valvetrains being eaten.

https://www.google.com/search?q=201...cam+replacement+site:www.jlwranglerforums.com

OK, again RIGHT SIDE..........
2018 was the first year for the PUG in the Wrangler line.
Where were they made?

Can the same search be done on the other vehicles with the PUG?
For example, WK2 and others? (trucks, cars, whatever)
Are the Grand Cherokee people seeing the same?
Where were the engines made.
(It matters, ask any repair person in various industries)

And is there any pattern as far as country of origin of the same issue is found with the PUG in other vehicles?

If I read the one JLU post correctly, the fool was only replacing two of the "lifters" (lash adjusters) and followers? Dumb idea. Asking for more trouble.

It would be interesting to know if anyone who did just the minimum replacements later had issues again since it's the exhaust lash adjusters that spray the intake followers and cam lobes. (or if there was a failure because they only replaced the followers that looked bad)


If I ever had a failure - I'd be replacing the intake cam, ALL of the followers ("rocker arms") and I would be comparing the exhaust lash adjusters to a brand new one to determine if the numbers were the same, or there were any issues with the part that could impede the oil spray.
As Benny says - some of the parts have changed over time - differing part numbers and so on. I'd be comparing very carefully like we do with all engine builds where parts have changed or different vendors are used.

 

[Hootbro]

OK, again RIGHT SIDE..........
2018 was the first year for the PUG in the Wrangler line.
Where were they made?

Can the same search be done on the other vehicles with the PUG?
For example, WK2 and others? (trucks, cars, whatever)
Are the Grand Cherokee people seeing the same?
Where were the engines made.
(It matters, ask any repair person in various industries)

And is there any pattern as far as country of origin of the same issue is found with the PUG in other vehicles?

If I read the one JLU post correctly, the fool was only replacing two of the "lifters" (lash adjusters) and followers? Dumb idea. Asking for more trouble.

It would be interesting to know if anyone who did just the minimum replacements later had issues again since it's the exhaust lash adjusters that spray the intake followers and cam lobes. (or if there was a failure because they only replaced the followers that looked bad)


If I ever had a failure - I'd be replacing the intake cam, ALL of the followers ("rocker arms") and I would be comparing the exhaust lash adjusters to a brand new one to determine if the numbers were the same, or there were any issues with the part that could impede the oil spray.
As Benny says - some of the parts have changed over time - differing part numbers and so on. I'd be comparing very carefully like we do with all engine builds where parts have changed or different vendors are used.

So what is your best guess to cause since we are all guessing to some degree not know the raw data?

 

[Charles 236]

The VVL rocker arms are oiled by oil sprayed from the exhaust rockers arms on both banks. All the rocker arms of both types (VVL intake and exhaust) are the same, there is no left intake rockers or right intake cams . There are two factors in oiling the high lift rockers, and how they last or fail, that I have observed.

First, the rotation of the camshafts in relation to the exhaust rockers on each side. Difficult to explain without diagrams, but I studied this and realized that on the left bank, the intake cam rotates about one fourth as far to get to the actual high lift cam lobe and high lift rocker arm contact points. On the tight bank, the cam must rotate three fourths more before the this contact point is reached. This allows that much longer for oil to sling off of the cam before reaching the high lift lobe and high lift rocker arm contact point. This is why the right bank is more likely to have an intake cam failure.

Secondly, this leads to the question, why some engines, such as '20 and up models, have more problems than earlier engines? Normally, earlier production engines are more likely to experience problems than later de-bugged engines. This is my theory, but I cannot prove it. I believe the quality of the exhaust rockers (and possibly other components, such as cams) went down for some reason. I suspect a change in vendors or change in manufacturing technique, or even possibly worn tooling, but I have no proof. I have removed exhaust rockers and checked the oil spray holes, and found inconsistent spray patterns on rockers that were opposite failed intake rockers. So, if the intake camshaft fails, I would want the exhaust rock(s) opposite the faied intake rockers replaced as well.

Finally, best preventative maintenance is oil changes with a high quality oil and filter. Bottom end failure is incredibly rare in 3.6 engines of any generation, so ignore the GM 6.2 oil change "doping " nonsense, it doesn't apply to any engine used in a Jeep.

 

[ShadowsPapa]

First, the rotation of the camshafts in relation to the exhaust rockers on each side. Difficult to explain without diagrams, but I studied this and realized that on the left bank, the intake cam rotates about one fourth as far to get to the actual high lift cam lobe and high lift rocker arm contact points. On the tight bank, the cam must rotate three fourths more before the this contact point is reached. This allows that much longer for oil to sling off of the cam before reaching the high lift lobe and high lift rocker arm contact point. This is why the right bank is more likely to have an intake cam failure.

I had to think a bit - huh? They are the exact same profile left intake to right intake cams.............. but then, I realized you were comparing rotation from spray.

I've seen you mention something like this before, and I wondered - but what about people like me, where every single trip, no exceptions, and some trips, every few miles, that engine sees 3,000-4500 RPM for a while........
I'm running in high lift mode - a lot. In low lift mode, that center section is only making contact with the cam's lobe by the light pressure of the spring in that intake follower. There's no pressure other than the spring pressure in low-lift mode, it's sort of just riding on it.
Then pop into high lift mode, and you have the full force of the valve spring up against it - a strong spring pushing that follower up hard against the cam.

So what is your best guess to cause since we are all guessing to some degree not know the raw data?

First - thanks for holding my feet to the fire.. I hadn't realized it but I think my feeling like crap is impacting my responses more than usual (although it's always there)

- not enough data.
Guesses (opinions, guesses, speculation) become fact on the internet. As much as I hate that, I don't really want to put something out there that gets repeated over and over, only to find wow, was that one way off!

I really want to know:
Are other Jeep/Ram/FCA vehicles seeing this?
If so - when did it start?
Have there been cases of 2024 and later models experiencing this?
Did the 2018-19 JL PUG come out of Mexico? ***

As I've said earlier - are there ANY instances of this happening to the PUG 3.6 where people were using an oil other than "specified" (not to BLAME, but as another point of reference - type, viscosity, base oil, miles between changes, other things)

The above just as data points - that would either align with others, or show "well, there goes that idea".

Maybe one reason I've not had any of my engine builds fail is that I am a total stinker, downright anal, on inspecting every part, every detail, and comparing old to new, replacements to originals. I check oiling before valve covers go on. I look for how the oil gets to where it's needed, any issues with design that I can improve on and so on.


*** It matters. 8 speed transmissions made by ZF in GERMANY had a lot of failures due to LEAKS. Sometimes it was the CASE, sometimes fittings, but they leaked, a huge, known issue.
The transmissions for Jeep made by FCA - no leaks.
Somewhere in one plant, there was a problem that didn't exist in another.
I can point to a lot of other cases as well, in vehicles, appliances and more.

 

[Charles 236]

When running in high lift mode, the oil pump is in high volume mode as well, so there is a considerable increase in oil pressure and volume to be sprayed on the intake cam. This would take care of the high lift mode causing an increase in pressure (mechanical pressure that produces friction)on the cam lobes and rockers. I have seen no evidence that running more in high lift mode wears the cams and rockers any more than running the higher RPMs in a classic 3.6 Pentastar wears cams
This is based on my observations, although it doesn't seem to make logical sense.

 

[Gatorac]

The VVL rocker arms are oiled by oil sprayed from the exhaust rockers arms on both banks.

I have removed exhaust rockers and checked the oil spray holes, and found inconsistent spray patterns on rockers that were opposite failed intake rockers.

This is probably the most intelligent and relevant information I've seen about this issue.

My 2020 has 38k miles on it now. I've had it since new and intend on keeping it for a long time. The cam/rocker issues have my attention. If I do end up having the issue, you can bet I'll take your advice about replacing the exhaust rockers across from the failed intake rockers. Thanks for sharing.

 

[ShadowsPapa]

When running in high lift mode, the oil pump is in high volume mode as well, so there is a considerable increase in oil pressure and volume to be sprayed on the intake cam. This would take care of the high lift mode causing an increase in pressure (mechanical pressure that produces friction)on the cam lobes and rockers. I have seen no evidence that running more in high lift mode wears the cams and rockers any more than running the higher RPMs in a classic 3.6 Pentastar wears cams
This is based on my observations, although it doesn't seem to make logical sense.

If I was working on one of my own - I'd see what could be done to "aim" and even increase volume in that area - do the exhaust followers restrict what gets shot out to the right side intake?
I wonder what might happen if one could lower the RPM point where the pump shifted modes - you don't need anything even close to 70psi - it's just not needed even in a performance V8, volume is needed, but it's apparent volume on the low side isn't enough to keep up.
Might be that a modification to the oil pump and controls would help.
I know some of us modify how the con rods shoot oil at the pistons and wrist pins in builds. I've notched rod bearings myself to modify oiling.

 

[Charles 236]

If I was working on one of my own - I'd see what could be done to "aim" and even increase volume in that area - do the exhaust followers restrict what gets shot out to the right side intake?
I wonder what might happen if one could lower the RPM point where the pump shifted modes - you don't need anything even close to 70psi - it's just not needed even in a performance V8, volume is needed, but it's apparent volume on the low side isn't enough to keep up.
Might be that a modification to the oil pump and controls would help.
I know some of us modify how the con rods shoot oil at the pistons and wrist pins in builds. I've notched rod bearings myself to modify oiling.

Back in the day, whenever I built a small block Mopar for high performance use, I had a modification that I made to the oiling system to guarantee that the timing chain received enough oil to stay well lubricated. I had found that my timing chains were wearing enough to allow the cam to retard a couple or three degrees and that there was excessive spark scatter. I knew that the timing was no longer steady, and the distributor was still tight, so the spark scatter had to be coming from the timing chain. When I checked, I found a slack chain. I ran these engines at 7,500 RPMs, so every little detail mattered in keeping it together and running strong. These engines needed more oil pressure, which was easy to get, but more volume would have resulted in filling the heads with oil faster than it could drain to the pan. The bottom end also got extra care, but the main thing was to keep oil on bearings and wear surfaces without emptying the pan.

The Pentastar already has an excellent oiling system design. The oiling holes in the exhaust rockers are aimed well enough in most cases. In the ones opposite failed intake rockers, it seems like there is a bit of restriction in the intake spray hole, maybe something foreign that the oil filter didn't catch. Sometimes they can be cleared with cleaner and high pressure air. It might be possible to "aim" the spray hole by drilling it with a pin vise.

As far as switching the oil pump to high volume mode at a lower engine speed, it is probably possible, but it would require working on the PCM programming. I don't know of any flash programmer that can be used, it probably would be a custom program. As for a mechanical way, the pump will default to high volume without the solenoid operating, but the PCM would set a DTC.

 

[Stan H]

The VVL rocker arms are oiled by oil sprayed from the exhaust rockers arms on both banks. All the rocker arms of both types (VVL intake and exhaust) are the same, there is no left intake rockers or right intake cams . There are two factors in oiling the high lift rockers, and how they last or fail, that I have observed.

First, the rotation of the camshafts in relation to the exhaust rockers on each side. Difficult to explain without diagrams, but I studied this and realized that on the left bank, the intake cam rotates about one fourth as far to get to the actual high lift cam lobe and high lift rocker arm contact points. On the tight bank, the cam must rotate three fourths more before the this contact point is reached. This allows that much longer for oil to sling off of the cam before reaching the high lift lobe and high lift rocker arm contact point. This is why the right bank is more likely to have an intake cam failure.

Secondly, this leads to the question, why some engines, such as '20 and up models, have more problems than earlier engines? Normally, earlier production engines are more likely to experience problems than later de-bugged engines. This is my theory, but I cannot prove it. I believe the quality of the exhaust rockers (and possibly other components, such as cams) went down for some reason. I suspect a change in vendors or change in manufacturing technique, or even possibly worn tooling, but I have no proof. I have removed exhaust rockers and checked the oil spray holes, and found inconsistent spray patterns on rockers that were opposite failed intake rockers. So, if the intake camshaft fails, I would want the exhaust rock(s) opposite the faied intake rockers replaced as well.

Finally, best preventative maintenance is oil changes with a high quality oil and filter. Bottom end failure is incredibly rare in 3.6 engines of any generation, so ignore the GM 6.2 oil change "doping " nonsense, it doesn't apply to any engine used in a Jeep.

Could it be that some engines that do well in excess of 100k have more precise oiling in the exhaust oil spray holes ?
I know alot of engine builders honestly and port and drill out many different passages . Could these oil spray holes be uniformed similar to how primer holes in a bullet case are cleaned and uniformed and how passage ways in heads are cleaned of burs etc to allow smooth flow of fuel and air ?

 

[Charles 236]

The oil spray holes could be "blueprinted" to "aim" the oil flow, but in an otherwise stock engine it probably wouldn't be worthwhile. Just checking each exhaust rocker spray hole for interference is more than most techs would ever do, especially on a warranty repair. If the holes are clear, there is just one more thing that really needs to be checked, the oil galley plugs behind and below the phasers. Make sure they are tight, when loose the oil pressure is reduced and this can affect the oil spray from the exhaust rockers.

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