Leaking Engine Oil Cooler

If you have a 3.6L Pentastar Jeep , Dodge, Chrysler, or Ram with this motor you likely have dealt with the dreaded Pentastar Leaking Engine Oil Cooler. If you have not yet this may be in your future. This leak is commonly misdiagnosed as a rear main seal, valve cover gasket, oil pan gasket, or even a cylinder head gasket. Although you may have these leaks as well, you should ensure that it has been properly diagnosed.

What is the Engine Oil Cooler?

Pentastar Oil Cooler
Pentastar Oil Cooler

The engine oil cooler as the name suggest cools the oil going through the engine. In the 3.6 Pentastar it also houses the engine oil filter, oil pressure sensor, and oil temperature sensor. Since it houses the oil filter it must be opened at every oil change and has o rings that must be replaced at every service. To access the engine oil cooler you must remove the upper and lower intake. The engine oil cooler mounts in the valley between the cylinder heads.

Common Failures

The pentastar engine oil cooler has several common failure points including:

  • Oil filter cap, or housing broken by over tightening
  • Oil Filter Bypass valve is plastic and breaks easily
  • Gaskets leaking, on top, and on cooler mount
  • Oil pressure sensor failing, Oil temperature sensor failing

What to do?

To start, Replace the Pentastar Leaking Engine Oil Cooler. Clean the residual oil to ensure no further leaks are overlooked. Typically when the oil cooler fails it will make quite a mess and make it easy to miss additional leaks. Have your vehicle serviced by Professionals who will not damage your oil cooler while changing oil. Ask your shop about replacing your spark plugs. You can save $200 – $400 in labor having this maintenance done while the intake is removed. Consider a spin on oil filter adapter.

–Joshua Shook Sr.