Pentastar 3.6 oil cooler failure. What really causes or exacerbates it?

I've found that the issue isn't really about over-torquing during filter changes. In fact, setting the filter cap to about 16-17 ft-lb is usually sufficient; there's no need to max out at 18 ft-lb. The real problem lies with the plastic oil filter housing supplied for these vehicles. It's simply not well-designed or well-made. I experienced a failure myself with a brand new Jeep at just 6000 miles. One evening, I noticed a smell of burnt coolant while driving. Despite using dye and a black light, I couldn’t locate the leak. However, after warming up the engine and literally sniffing around the center of the engine compartment, I pinpointed the source. I ended up replacing the faulty housing with a Dorman aluminum unit made in Malaysia, and since then, I’ve had no issues with smells, leaks, or anything else. Now, I make sure to tighten the oil filler cap to 17 ft-lb with each oil change and use Mopar gaskets for the housing.

As for the Baxter plus, it seems like it's a solution looking for a problem. I’ve looked into it too. Perhaps the version with the filter relocation kit might be useful, but I would avoid the model with the filter on top. It's quite heavy and could potentially introduce more issues. Also, the argument about preventing "dry starts" doesn't hold much water for me. Unless your engine sits idle for weeks, you're unlikely to hear any lifter clatter. Even with a Baxter unit, lifters can still bleed down over time.
The spin-on filter on top of the adapter is pretty goofy - it just seems like more stress on the unit - not less.
How do you know if the Dorman will be made in Malaysia?
 
The spin-on filter on top of the adapter is pretty goofy - it just seems like more stress on the unit - not less.
How do you know if the Dorman will be made in Malaysia?
It says on the box and on the filter housing unit. Funny enough, when I got a Made in USA unit I was very excited. Then when I opened the box I was sorely disappointed.

Funny enough, Hyundai uses a similar oil filter housing setup on their V6 Lambda series engines (including the expensive Bi-Turbo model). Theirs doesn't have an oil heat exchanger and it's supplied by MAHLE. Guess what? They never leak, they don't have any issues. Unless you install the oil filler cap with a breaker bar, you can even over-torque it and it won't break. Then again, it's supplied by MAHLE, not by random Chincon supplier.

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It says on the box and on the filter housing unit. Funny enough, when I got a Made in USA unit I was very excited. Then when I opened the box I was sorely disappointed.

Funny enough, Hyundai uses a similar oil filter housing setup on their V6 Lambda series engines (including the expensive Bi-Turbo model). Theirs doesn't have an oil heat exchanger and it's supplied by MAHLE. Guess what? They never leak, they don't have any issues. Unless you install the oil filler cap with a breaker bar, you can even over-torque it and it won't break. Then again, it's supplied by MAHLE, not by random Chincon supplier.

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Yeah - wish the 3.6L had a half normal oil cooler …
Not even like it’s a great place for heat to dissipate …
 
Yeah - wish the 3.6L had a half normal oil cooler …
Not even like it’s a great place for heat to dissipate …
It's not an oil cooler really, it's an oil heat exchanger. It's meant to warm up the oil and keep it in sync with the coolant temperature. The problem is that it does a very poor job at that, and it's unnecessary given where the oil filter housing is installed - that's why Hyundai didn't bother with an oil heat exchanger on their V6 engines.

A true oil cooler would be a radiator at the front with engine oil passing through it, like the SRT models have.

On the Pentastar, only ~50% of the oil goes through the heat exchanger, the other half bypasses it. That's why it's a bad design. Basically they half-arsed an already bad design, and made it worse. Otherwise, the Pentastar is a decent engine. I like it for what it is.
 
Not that I’ve ever seen them leak lol. But usually looks like the round cap things at the bottom and or front o ring. New ones come with a red o ring for the “older” applications like 14-22 apparently the black one they had been shipping them with is not correct size
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Not that I’ve ever seen them leak lol. But usually looks like the round cap things at the bottom and or front o ring. New ones come with a red o ring for the “older” applications like 14-22 apparently the black one they had been shipping them with is not correct size View attachment 218950
It appears you have no trouble getting the sensors out? I am hoping to reuse my old sensors in the new Dorman unit. I will be using MOPAR O-rings.
 
It's not an oil cooler really, it's an oil heat exchanger. It's meant to warm up the oil and keep it in sync with the coolant temperature. The problem is that it does a very poor job at that, and it's unnecessary given where the oil filter housing is installed - that's why Hyundai didn't bother with an oil heat exchanger on their V6 engines.

A true oil cooler would be a radiator at the front with engine oil passing through it, like the SRT models have.

On the Pentastar, only ~50% of the oil goes through the heat exchanger, the other half bypasses it. That's why it's a bad design. Basically they half-arsed an already bad design, and made it worse. Otherwise, the Pentastar is a decent engine. I like it for what it is.
Um...Hyundai oil heat exchanger is in the radiator.

OE's never use full flow oil coolers/exchangers. They usually use some sort of restricted flow with a bypass valve. Restricted flow is there to reduce dynamic pressure in the cooler so that the cooler isn't subjected to the normal high pressure and pressure fluctuations during engine operation. A cooler subjected to constant fluctuations between 15psi hot idle and 80 psi cold under load, and everything inbetween wouldn't be very durable. A bypass valve is in place so that engine lubrication isn't dependent on flow through the cooler, whether the cooler becomes clogged, restricted, or the cooler thermostat malfunctions. Engine oil supply is priority, as it should be.

There's nothing unique about the pentastar's oil cooler basic function. It's just a different implementation of the same concepts everyone else is using.
 
Um...Hyundai oil heat exchanger is in the radiator.

OE's never use full flow oil coolers/exchangers. They usually use some sort of restricted flow with a bypass valve. Restricted flow is there to reduce dynamic pressure in the cooler so that the cooler isn't subjected to the normal high pressure and pressure fluctuations during engine operation. A cooler subjected to constant fluctuations between 15psi hot idle and 80 psi cold under load, and everything inbetween wouldn't be very durable. A bypass valve is in place so that engine lubrication isn't dependent on flow through the cooler, whether the cooler becomes clogged, restricted, or the cooler thermostat malfunctions. Engine oil supply is priority, as it should be.

There's nothing unique about the pentastar's oil cooler basic function. It's just a different implementation of the same concepts everyone else is using.
Thank you for saying this. Sometimes people don't understand thermodynamics. There are a lot of engines which use oil-to-water coolers/heaters. All of the big 3 do, and most imports do.
 
And in our own group…

 
We've discussed this a bunch over the years here.

It's pretty rare you'll find with 100% certainty where your oil leak came from on a pentastar filter/cooler assembly. Access to it requires totally disabling the engine, so you can't "test" it. Visual to it requires an endoscope cam and actually being able to see anything with one once a leak is identified is impossible, because the engine block valley is going to be full of oil from the leak, which submerges and hides the base of the filter/cooler assembly.

Watch any of the Chrysler, Dodge, Jeep mechanic channels and they will confirm this. Cracks in the plastic is rare. Some claim to have seen leakage out of the "glued" in plugs on the housing, or leaks from where the oil temp or oil pressure sensors thread in. The rest of the leaks seem to originate from the O-rings seals on the bottom of the unit, that get sandwiched between the unit and the engine block.

My theory is movement of the plastic over time causes the O-rings to fail. Be it thermal movement or possible degradation of the plastic over time in the sealing areas. Just like the plastic cooling system components that leak on these engines, I'd rather mate up a chunk of aluminum to an aluminum head/block, than try to bolt a piece of plastic to it.
Thermal movement is alway a partial cause, or the whole ball of wax. Been selling Phenolic repairs on Euros for 30 years. They are cheaper to manufacture, and that is all they care about.
 
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