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

[LouisvEarlleJT]

I can't lay under a vehicle any more and look up at the underside without getting really sick - so I'm really limited since I lost the functionality of my left inner ear/balance.
Ticks me off as I've got so much to do, including on my cars where almost everything requires being UNDER them.

Quality? The paint on my 25 is absolutely horrible compared to my 22. It's like it was sprayed in a local shop.
When I was wiping down the door sill area to put some clear paint film protection on the sill area, the rubbing alcohol dissolved the paint on the sill.
i assume it failed inspection after assembly and they did some touchup?
Paint should not come off on a paper towel with cheap rubbing alcohol.

I’d bet that is just some overspray that you wiped off, don’t know what order they paint these things in but I’d make sense to do the can/roll bar then doors/hinges/exterior, who knows.

Sponsored

 

[ShadowsPapa]

Ok, serious question. What changed in the pentastar 3.6 to move from 5w30 to 0w20? I mean this isn't a new design or new engine... so... why did it change?

Yes, it is a new design. MUCH changed, in fact there's a multiple page document with the changes.
VVL added, VVT methods changed, crankshaft bearings are quite different - sizes, materials and so on, 2-stage oil pump.
Things are monitored closely - including valve lift stage, CCDIFF and more.

Valve guides are shorter, different springs, totally different timing chain and sprocket design......... it's a long list.
The PUG was introduced in 2015 for the 2016 model year of Grand Cherokee and some others.
JK still used the old design 3.6
Wrangler didn't get the new design until 2018 (JT from day 1)

And I have to laugh my ass off when i see attorneys and other jokers trying for class action suites claiming that the valve train issues have been going on since 2012. Sorry, there were failures, but very different parts and very different causes. Pre-PUG engines didn't have VVL, and they used different rollers.
Guess what performance people have moved away from for their roller lifters and cams - needle bearings. They've gone to bushings as the needle bearings couldn't handle the IMPACT forces. In the first generation of Pentastar 3.6........ those needle bearings gave out.

Interesting to note is that the 3.6 Pentastar engine for JT was made in Mexico - until the 2024 model year - so, let's keep close watch on the 24 and later engines for cam issues.
I also find it interesting that the vast majority - not all, but absolutely most - cam failures were 2020 and earlier 2021 models.
The issue isn't as bad as it was for the 2020s.
I'm decent at trends and pattern recognition and owning a 2020, then a 2022 and now a 2025, my concerned dropped quite a bit with each passing model year.

A poll might be interesting - who here had a cam failure in any of their JTs and if so, what model year was it.

Before someone jumps in and says - but.........but...........but.......... the 23s and 24s are too new to know yet!
Wrong - go back in history 4 to 5 years in this forum. You will find 2020 model years, not even a year old, not even 20,000 miles, with cam failures. It was coming up fairly often in my first few months here!


I'm sticking to the specs - IF I did change, it would be only to a 0w30 at the most.
I want that oil to move and move fast through the system when it is first started even at 50 degrees.

GM in Europe is in big trouble because their rules state that a vehicle that is designed for a specific oil, and comes out with a specific oil, must run the remainder of it's' life on that same oil.
In other words, GM is getting by - literally CHEATING customers/owners - but in the EU, this won't fly. Sorry, GM - you must fix it so that it will again run on 0w20. Don't pass go, don't collect $200 - go straight to jail.

 

[ShadowsPapa]

I’d bet that is just some overspray that you wiped off, don’t know what order they paint these things in but I’d make sense to do the can/roll bar then doors/hinges/exterior, who knows.

Painted as a unit - body, hood, doors, windshield frame, roll cage, all of it. Grill and roof added later.

It was only on the right front door sill area where the paint came off and it looked a bit different.

I suspect a flaw was found and addressed with "touch-up paint".

 

[Deleted member 67086]

Why are people comparing two very very different engines?
They aren't even close other than they both burn gasoline and make things go.

Here's what insiders are saying - The problem has to do with connecting rod and crankshaft components with unspecified manufacturing defects.
It doesn't cover 2025 model year.

“A series of crankshaft and connecting rod manufacturing improvements implemented on or before June 1st, 2024, addressed contamination and quality issues. Model-year 2025 vehicles were built after these improvements and are not included in the recall.”



You likely know that the numbers, W and other, overlap a lot in measured viscosity so you really haven't ventured out of the yard very far.



Where's the popcorn and where's that chairman?
Is this a "here we go again thing?

What GM is doing is tossing a BAND AID at the problem with the change in oil viscosity. It's so funny - gee, we have defective parts, we'll put some tape over it for you with heavier oil.
And this will lead people to believe - gee, I should run heavier oil, too! GM is fixing their problem with it.
No, they are making customers shut up and go away - they are still running defective engines!
What a hoot.

If all GM was doing was changing to 0w40 oil, I would agree with you, they're just putting a bandaid on the problem. But before they ever get to the oil viscosity change, they are running tests to see if they see any deviation in alignment between the cam shaft and the crankshaft. If they do, they are saying that is an indication that there is a problem, and they are basically replacing the engine.

If they do not see a deviation, THEN they are recommending the change to 0w40, I suppose in hopes that it may prevent a future failure. If it doesn't, and a failure still occurs in the future, then I assume they will fix it under the recall. This seems reasonable since not all engines are affected.

I am quite sure this caught the attention of Jeep owners because it seems plausible that the Pentastar cam issues could be tied to an oil issue, and they'd gladly change viscosity if it lowered the chance of them having to deal with that issue.

 

[ShadowsPapa]

We Always ran 0/30 in 15 rubicon runs like new in fact better than new with 200k 0/20 is to thin its about the sound to a common sense approach.

2015 is a very different engine, Can't compare. the PUG was made with 0w20 in mind.
In very hot climates you really haven't moved far away from 20 by going to 30.

It would be interesting to do some actual comparisons - track oil and engine temperatures with one grade, then pop up a notch and see if the engine temperature or oil temperature climb.
IF they do, then back it down. If not - leave it.

 

[DrewsJT]

If all GM was doing was changing to 0w40 oil, I would agree with you, they're just putting a bandaid on the problem. But before they ever get to the oil viscosity change, they are running tests to see if they see any deviation in alignment between the cam shaft and the crankshaft. If they do, they are saying that is an indication that there is a problem, and they are basically replacing the engine.

If they do not see a deviation, THEN they are recommending the change to 0w40, I suppose in hopes that it may prevent a future failure. If it doesn't, and a failure still occurs in the future, then I assume they will fix it under the recall. This seems reasonable since not all engines are affected.

I am quite sure this caught the attention of Jeep owners because it seems plausible that the Pentastar cam issues could be tied to an oil issue, and they'd gladly change viscosity if it lowered the chance of them having to deal with that issue.

Actually there's a new service bulletin after the 0w-40 TSB.

 

[jav_eee]

It would be interesting to do some actual comparisons - track oil and engine temperatures with one grade, then pop up a notch and see if the engine temperature or oil temperature climb.
IF they do, then back it down. If not - leave it.

I’ve been running 5w30 for the past 2 changes. I also have the RPM fan controller (I’m sure this will add another 10 pages to this thread) but highest I see is 203° oil (takes a while to get there) and 206° coolant.

I’ll go back to 0w20 for the summer months and see what the temps look like then…

 

[ShadowsPapa]

If all GM was doing was changing to 0w40 oil, I would agree with you, they're just putting a bandaid on the problem. But before they ever get to the oil viscosity change, they are running tests to see if they see any deviation in alignment between the cam shaft and the crankshaft. If they do, they are saying that is an indication that there is a problem, and they are basically replacing the engine.

If they do not see a deviation, THEN they are recommending the change to 0w40, I suppose in hopes that it may prevent a future failure. If it doesn't, and a failure still occurs in the future, then I assume they will fix it under the recall. This seems reasonable since not all engines are affected.

I am quite sure this caught the attention of Jeep owners because it seems plausible that the Pentastar cam issues could be tied to an oil issue, and they'd gladly change viscosity if it lowered the chance of them having to deal with that issue.

LOL - that testing for deviation is to determine if there is BEARING/CRANK damage.
Nothing to do with anything else at all and it can't apply to our engines.
If we had a CCDIFF issue, then it would be time to look for worn bearings (or other issues in the valvetrain)
You are interpreting the reasoning for their testing wrong - it's to determine crankshaft issues, nothing to do with the valve train.


Wow, unreal how people are looking at the GM thing and trying hard to connect it to FCA cam issues. Very different..

Did you know that back in the late 1970s and 1980s, AMC devised a method to test engines very similar to what GM is doing with these?
They mechanically spun the engine in a stand. They had oil pressure monitoring throughout the engine's oil galleries. They knew exactly where the pulses of oil pressure should come compared to exactly where the crankshaft was in its rotational circle. They could tell if there was a loose bearing, oil gallery issue and more.
And that's what GM is doing - if they find that the cam/crank relationship is off, it's due to a crankshaft issue - they are measuring where the piston is compared to the valves and so on.

There's zero connection to our engines. it's not at all related.
GM testing is to determine if there is already excessive crank journal and/or bearing wear by looking for things to be positioned just right. Science, geometry, trig, and so on. It's also hydraulics and the science of protecting surfaces - GM screwed the pooch and is now paying the price and ripping off customers.
If I owned one of them, since GM knows it's an issue, they know the cause is on them, I'd be all over them for a new engine and going back to the oil that it's supposed to run. I won't accept bandaids tossed out by the bean counters trying to hide the real problem and slide by.

It caught the attention of Jeep owners who really have no clue about how any of this works, have never built engines for a living, and never been involved in the in-depth testing done by automakers.
People are looking for reasons, trying so very hard to connect the dots - dots that are a long ways apart.

GM's testing is to determine crankshaft wear - they use the cam position to aid in that.

GM's problem wasn't the oil,
it was the idiots making crankshafts and then passing them through inspection.

Stop trying to read more into it.

 

[ShadowsPapa]

I also have the RPM fan controller (I’m sure this will add another 10 pages to this thread) but highest I see is 203° oil (takes a while to get there) and 206° coolant.

It's your engine - feel free to sludge it up and shorten the oil life.
That's a part I'll never understand - why people insist on running engines cold - but that's aside from the oil bit.

Higher viscosities have higher friction - sheer, and generate more heat in the bearing areas. They also flow more slowly, meaning they "may" or "can" make the oil (and engine) run hotter.

 

[jav_eee]

It's your engine - feel free to sludge it up and shorten the oil life.

Well i change the oil every 5k (or sooner sometimes) and I probably won’t keep the jeep for that long. Won’t be my problem when the sludge finally happens haha

Makes me feel better when I’m driving around in the 110° Deep South Texas heat.

 

[ShadowsPapa]

Well i change the oil every 5k (or sooner sometimes) and I probably won’t keep the jeep for that long. Won’t be my problem when the sludge finally happens haha

Makes me feel better when I’m driving around in the 110° Deep South Texas heat.

You are one reason that you can't make a "blanket statement" on oils - TEXAS heat.
Likely going up one "notch" in the oil is putting is pretty close to where many others are much of the time.
I've seen some charts that compare viscosities of oil over temperatures and there's a lot of overlap in some areas. I don't see one "notch" change a big deal in extreme heat.

Here I would never go up on the lower number (0w) as I want that oil to move and move fast when it's 20 degrees out.

 

[Deleted member 67086]

LOL - that testing for deviation is to determine if there is BEARING/CRANK damage.
Nothing to do with anything else at all and it can't apply to our engines.
If we had a CCDIFF issue, then it would be time to look for worn bearings (or other issues in the valvetrain)
You are interpreting the reasoning for their testing wrong - it's to determine crankshaft issues, nothing to do with the valve train.


Wow, unreal how people are looking at the GM thing and trying hard to connect it to FCA cam issues. Very different..

Did you know that back in the late 1970s and 1980s, AMC devised a method to test engines very similar to what GM is doing with these?
They mechanically spun the engine in a stand. They had oil pressure monitoring throughout the engine's oil galleries. They knew exactly where the pulses of oil pressure should come compared to exactly where the crankshaft was in its rotational circle. They could tell if there was a loose bearing, oil gallery issue and more.
And that's what GM is doing - if they find that the cam/crank relationship is off, it's due to a crankshaft issue - they are measuring where the piston is compared to the valves and so on.

There's zero connection to our engines. it's not at all related.
GM testing is to determine if there is already excessive crank journal and/or bearing wear by looking for things to be positioned just right. Science, geometry, trig, and so on. It's also hydraulics and the science of protecting surfaces - GM screwed the pooch and is now paying the price and ripping off customers.
If I owned one of them, since GM knows it's an issue, they know the cause is on them, I'd be all over them for a new engine and going back to the oil that it's supposed to run. I won't accept bandaids tossed out by the bean counters trying to hide the real problem and slide by.

It caught the attention of Jeep owners who really have no clue about how any of this works, have never built engines for a living, and never been involved in the in-depth testing done by automakers.
People are looking for reasons, trying so very hard to connect the dots - dots that are a long ways apart.

GM's testing is to determine crankshaft wear - they use the cam position to aid in that.

GM's problem wasn't the oil,
it was the idiots making crankshafts and then passing them through inspection.

Stop trying to read more into it.

Um, I believe you are the one reading into things here. I am fully aware that GM's deviation testing was for their bearing issues they are having, and is not the same issue that Jeep is having.

I also said the reason the GM issue likely caught the attention of Jeep/Pentastar owners was that some feel their cam issues could be an oil related issue. I did not say it was the issue, I just said it likely caught their attention because it seemed plausible. Based on the many discussions on here regarding 0w20, you know this not a new theory.

You've made it clear that you feel GM's issue is parts related and is in no way related to oil. You've mentioned that before in other posts. I would tend to agree, but for whatever reason GM felt a change in viscosity was warranted as a preventative measure on engines that are not showing a current indication of a problem. If it doesn't prevent anything, I don't see what the big issue is, they will still fix the issue if the bearings still fail, just like are for engines that currently have an issue.

Okay, since people do not have your infinite wisdom on what the root cause of the current Gladiator Penastar cam failure is, please reply and let us all know so we can end all the speculation on this forum.

 

[ShadowsPapa]

You've made it clear that you feel GM's issue is parts related and is in no way related to oil. You've mentioned that before in other posts. I would tend to agree, but for whatever reason GM felt a change in viscosity was warranted as a preventative measure on engines that are not showing a current indication of a problem. If it doesn't prevent anything, I don't see what the big issue is,

The problem is the finish on the crankshaft (among other things).
They are avoiding fixing it for the masses - by saying "use sawdust in the transmission and it will quite it down" and they'll address failures from there.
The change in viscosity is only necessary because of the crank finish. No other reason.

Otherwise, they'd tell all other owners they also need to switch. This is limited to the engines - 21-24 - that have the shitty crankshaft. In the old days, crappy stuff was resolved with engine honey - STP and so on. In a way, GM is doing that.
They are putting off failures. Granted, some may not fail within the warranty period and GM will have skated by on those.
It's very much like an engine that had a manufacturing mistake where the bearing clearance was 0.035 instead of 0.025. Say they produced 100,000 of them that way. They can "fix" poor oil pressure by upping the viscosity - but that doesn't fix the problem, it masks it.

GM's upping the viscosity is to keep the rough sandpaper crankshaft with a lot of rough peaks in the finish more away from the bearings. Normally some of the oil 'squeezes" out on the combustion stroke - they don't touch, but do get a bit closer.
GM can't afford that to happen - so they are basically forcing the issue instead of fixing it.

Those engines DO STILL HAVE THE PROBLEM! They have crappy crankshafts. So they absolutely DO have the problem or issue - they are putting off having to deal with the damage done by the poor finish - pushing it ahead, in short, GM is kicking the can down the road.

I don't see what a GM crankshaft finish being crappy and risking ripping up bearings has to do with cam shafts.
Bearings and cranks operate under very different conditions and pressures. The finish is crappy on the crank.

It's quite simple. GM is kicking the can down the road - and saying "there's no problem unless there's a problem".

the recall has no impact outside of the listed dates - and the recommended oil in the book is still fine. What's that tell you? GM is masking a problem, a man-made issue on very specific engine built between very specific dates!
It's a mask, a bandaid - NOT A FIX.

6.2L V8 engines and produced between March 1, 2021, to May 31, 2024, showed a higher rate of failure claims, according to the NHTSA report.

After being notified of the NHTSA’s probe earlier this year, GM sequentially launched another investigation into the issue. Its latest teardown analysis identified two primary problems: “rod-bearing damage from sediment on connecting rods and crankshaft-oil passages” and “out of specification crankshaft dimensions and surface finish.”

And why is there sediment in those oil passages? It's the debris from the crankshaft's rough finish being worn and scoured and it plugs the oil passages in the rods (which is the path the oil takes when the rod hole lines up with the crankshaft hole, to lube the upper end of the assembly)

All you have to do is look at all of their other engines outside of that short batch of years and see - look, they did NOT change viscosity on those! So they are admitting they screwed up, and are putting off any real fix.

 

[ShadowsPapa]

Okay, since people do not have your infinite wisdom on what the root cause of the current Gladiator Penastar cam failure is, please reply and let us all know so we can end all the speculation on this forum.

Unlikely to have a single 'root cause". Also note that the cam failures have dwindles in numbers since the 2020 model year. They changed cam numbers and lash adjusters.
There's not enough reliable information at this time. Will be interesting to see if the 24 and later years have the same issues since they moved production of the JT engines to the states, out of Mexico for the 24 model year.

 

[DiehardTory]

HI All, New Info.. there is a 3rd notice - not public yet per this youtube video.. look and see.

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