All Things Being Equal, Opt For The Longer-Lasting Part

Dear Car Talk:

I have a 2015 Dodge Durango with a 3.6L V6 engine. The SUV has 75,000 miles on it, and I plan to keep it for a long time.

I was told the oil cooler was starting to leak a little and will probably need replacement. I have heard that this is an issue with this engine since the cooler housing is plastic.

My question is: If I have to replace the oil cooler, should I replace it with the OEM plastic oil cooler or an aftermarket all-aluminum oil cooler? The price is roughly the same.

Thanks. -- Scott

I'd probably opt for the aluminum one, Scott. This oil cooler is probably the first place we'd look if you drove in with an oil leak and had one of these engines. It is pretty common.

The oil cooler sits on top of the engine, in between the two banks of "V"-shaped cylinders. It takes in both engine oil and coolant and uses the coolant, in an adjacent channel, to drain heat from the oil, then circulates the oil back to the engine and the coolant back to the radiator.

The oil cooler is actually part plastic and part metal. And it can leak for one of two reasons. Either the housing itself can fail (i.e., crack) or the seals can fail. There are small O-rings, where the cooler's oil channels mate up with the engine, and those often fail and let oil leak out.

It'd be nice to know which of those is causing your leak, Scott. Because if it's just the seals, that means the plastic didn't fail. And we never want to cast aspersions on innocent plastic. But once you've done the labor to remove the thing and inspect it, you might as well just replace the whole unit. And if I was replacing my oil cooler and had the option of plastic or aluminum, I'd probably get the aluminum one.

Keep in mind, your Dodge dealer will probably not install an aftermarket part for you. So, you'll have to go to Dodo's Dodge Depository and Dance Studio and ask an independent mechanic to put it in for you.

You won't get the benefit of the dealer's experience in doing thousands of these repairs. But you'll probably get a longer-lasting part and will definitely get a cleaner driveway.

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