3.6 pentastar as bad as it seems ???

[4WD]

Yes, that's because it has a two stage oil pump.

Again, the rocker failures have nothing to do with oil, oil pressure or anything else lubrication related. It's just poorly made parts. Some will last 200k and more and some will need changing.

Had those pumps in everything since 2013 and absolutely none of them behave with no logic like my Jeep - low RPM and low load - Boom - 80 psi meaning it’s over built and bypassing to have high pressure at low RPM.
I did not respond to valve train issues.

 

[INTENSE]

Out of the blue with an easy and well maintained 105k miles on our ‘21 Wrangler that I’m really partial to…we now have a tick. Man, I thought I might have made it past the “defective” part phase.

There doesn’t seem to be a definitive reason online and it seems they still haven’t come up with a solution despite a new rocker arm shaft but given the slack/noise…I wonder about the lash adjusters/lifters. That could hammer a marginal design in my experience. Maybe the aftermarket will investigate eventually.

The modern combustion engine has been around, what …140 ish years and this can’t be figured out…or is it planned obsolescence? Well, they better figure ICE out again because it looks like they won’t be getting people into that many electric vehicles like they calculated.

 

[midironman]

Out of the blue with an easy and well maintained 105k miles on our ‘21 Wrangler that I’m really partial to…we now have a tick. Man, I thought I might have made it past the “defective” part phase.

There doesn’t seem to be a definitive reason online and it seems they still haven’t come up with a solution despite a new rocker arm shaft but given the slack/noise…I wonder about the lash adjusters/lifters. That could hammer a marginal design in my experience. Maybe the aftermarket will investigate eventually.

The modern combustion engine has been around, what …140 ish years and this can’t be figured out…or is it planned obsolescence? Well, they better figure ICE out again because it looks like they won’t be getting people into that many electric vehicles like they calculated.

Based on updated TSB 09-011-25, appears to be a cam/rocker manufacturing issue from parts supplier.

 

[Fordiesel69]

I really like the engine overall. It is very powerful when paired with a 845re / 850re and is very acceptable to drive. There are some serious issues to consider prepping for.

-early models had left bank head failure that would stick and burn valves.
-all models will have a plastic oil cooler fail. Some earlier than others. Dorman makes a good aluminum upgrade and you can use the good oem rings.
-the cam and roller rockers can fail. Not common on the ram pickups, more common on jeeps and mini vans. Nobody can answer why.
-I personally have bid on and did quick look overs of municiple owned jeeps and ram trucks and can tell you that I personally correlate good timely oil changes and a lack of engine idle hours to strongly contribute to a long life. Conversely extended idle and extended drain intervals almost assure you will experiance failure.

 

[Cruisin'n5thgear]

Great points. I do a 5k mile OCI on our 2013 JKU, minimal idle time. Hoping for the best. 90k miles at the moment.

 

[tiger862]

Be careful as if you have an intake cam failure on 19 up, they are on infinite backorder.

 

[Fordiesel69]

Be careful as if you have an intake cam failure on 19 up, they are on infinite backorder.

any aftermarket?

 

[midironman]

any aftermarket?

Not as yet

 

[JTK]

Be careful as if you have an intake cam failure on 19 up, they are on infinite backorder.

I watched that Pine Hollow Diagnostics video. I didn't look into it, but I think that version of the pentastar may be different than most. That particular Wrangler Rubicon pentastar 3.6L had some type of variable valve lift situation. That was the cam and followers that were bad and basically on indefinite back order. Either way, with the amount of pentastars out there and the relative reliability of them, this shocked me more than the usual back ordered parts.

 

[tiger862]

Be careful as if you have an intake cam failure on 19 up, they are on infinite backorder.

I watched that Pine Hollow Diagnostics video. I didn't look into it, but I think that version of the pentastar may be different than most. That particular Wrangler Rubicon pentastar 3.6L had some type of variable valve lift situation. That was the cam and followers that were bad and basically on indefinite back order. Either way, with the amount of pentastars out there and the relative reliability of them, this shocked me more than the usual back ordered parts.

I looked it up and it supercedes to a 500 cam. Mc Kenly Texas shows it. Claims it can be ordered. Applies to most 3.6l other than Caravan.

https://parts.chryslerjeepdodgecity...IT-Intake-Left-Side/142437349/68661146AA.html

 

[4WD]

I really like the engine overall. It is very powerful when paired with a 845re / 850re and is very acceptable to drive. There are some serious issues to consider prepping for.

-early models had left bank head failure that would stick and burn valves.
-all models will have a plastic oil cooler fail. Some earlier than others. Dorman makes a good aluminum upgrade and you can use the good oem rings.
-the cam and roller rockers can fail. Not common on the ram pickups, more common on jeeps and mini vans. Nobody can answer why.
-I personally have bid on and did quick look overs of municiple owned jeeps and ram trucks and can tell you that I personally correlate good timely oil changes and a lack of engine idle hours to strongly contribute to a long life. Conversely extended idle and extended drain intervals almost assure you will experiance failure.

What’s the latest on this motor …?

 

[jkasch]

My bad. Posted in wrong forum.

 

[Donald]

Pondering about getting a jeep wrangler . New. 2 door Sport. Power nothing. Plain Jane. But dam there’s a lot of bad reviews on these engines. Are they as bad as advertised ???!

People love their Jeeps but they are listed near the bottom for reliability.

I had a 2001 Jeep Grand Cherokee that I loved. People with Jeeps like Wranglers love their Jeeps to a higher degree than those with Jeep Grand Cherokee.

I put a reman 4.0 engine in mine due to a cracked piston skirt that grenaded the engine. Still loved it however. (Love my current pickup even more however).

 

[INTENSE]

Based on updated TSB 09-011-25, appears to be a cam/rocker manufacturing issue from parts supplier.

Yep. I picked up my Wrangler 3.6 the same day that TSB started making rounds in social media. In case someone comes along looking for info, the mileage limit for “goodwill” reimbursement is 100k miles.

 

[INTENSE]

I really like the engine overall. It is very powerful when paired with a 845re / 850re and is very acceptable to drive. There are some serious issues to consider prepping for.

-early models had left bank head failure that would stick and burn valves.
-all models will have a plastic oil cooler fail. Some earlier than others. Dorman makes a good aluminum upgrade and you can use the good oem rings.
-the cam and roller rockers can fail. Not common on the ram pickups, more common on jeeps and mini vans. Nobody can answer why.
-I personally have bid on and did quick look overs of municiple owned jeeps and ram trucks and can tell you that I personally correlate good timely oil changes and a lack of engine idle hours to strongly contribute to a long life. Conversely extended idle and extended drain intervals almost assure you will experiance failure.

I can agree it can mitigate but there’s no pattern. Some picky owners out there still have failures and the earliest I’ve heard of was in the 20k+ range so that wouldn’t even be enough time for the typical daily driver to develop an issue if it were just oil changes and/or quality oil.

So with that, and given the TSB covers BOTH banks…and there’s only a part # revision on Bank 1 that may or may not be a physical change vs them now packaging the cams with rockers included still points to a difference from right to left given the predominance of Bank 1 failures compared to Bank 2. I do hope they changed the parts for Bank 1 though.

 

[vwthingman]

My 2018 Wrangler has over 100K miles and no issues with the engine. Replaced a radiator and that’s it. My UOA always comes back great as well. Love my first Jeep.

 

[4WD]

My 2018 Wrangler has over 100K miles and no issues with the engine. Replaced a radiator and that’s it. My UOA always comes back great as well. Love my first Jeep.

That’s good info - it took me 5 years to make 40k - wish I knew there was a “best oil” - but if I put miles on something else it shouldn’t be a significant worry …

 

[meep]

Man idk. I liked the pentastar as it sat in the square body town and country. A very good friend has one in his gladiator which is a pretty heavy vehicle for the v6 - I think his weighs in at over 6500 lbs - enough to get the commercial tax break. It seems smoothly balanced, has no problem revving, shifting, getting the job done, and staying out of the way. The engine and trans tuning is really good. And it still pulls all that vehicle very eagerly up gnarly inclines and angles.

 

[4WD]

Man idk. I liked the pentastar as it sat in the square body town and country. A very good friend has one in his gladiator which is a pretty heavy vehicle for the v6 - I think his weighs in at over 6500 lbs - enough to get the commercial tax break. It seems smoothly balanced, has no problem revving, shifting, getting the job done, and staying out of the way. The engine and trans tuning is really good. And it still pulls all that vehicle very eagerly up gnarly inclines and angles.

That is allot - my JLU is like 4500 lbs …

 

[hemioiler]

A very good friend has one in his gladiator which is a pretty heavy vehicle for the v6 - I think his weighs in at over 6500 lbs - enough to get the commercial tax break.

That doesn't sound right to me, my half ton doesn't even weigh that much. The GVWR of the rubicon is only 6250 so subtract about 1000 or more off of that to estimate curb weight.