6.4L EGR Cooler Testing

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

If the cooling system has been losing coolant and there are no external leaks showing, the EGR cooler may be leaking internally.

First perform a cooling system pressure test. Refer to DIAGNOSIS AND TESTING .
With the engine off and cool, check the exhaust system for coolant. The pressure test may force the coolant into the exhaust system if the EGR cooler has an internal leak.
NOTE:
Do not exceed the pressure indicated on the pressure cap during testing.

Courtesy of CHRYSLER GROUP, LLC
Remove the two EGR cooler exhaust gas inlet retaining bolts (2) and separate the cooler (1) from the exhaust system (3) and check for signs of coolant loss.
If the leak has not been found, using this method, it may be necessary to remove the EGR cooler and perform a bench test.