Failure mode - Ram 1500 EcoDiesel 3.0L V6 (2014-2019)
Oil cooler oil/coolant cross-contamination
Reliability tier: aggregated - verify before ordering, see /disclosure/
Symptoms
- coolant and oil cross-contamination (milky residue, oil floating in the degas bottle)
- rising temps, repeated contamination after flushes - the cooler keeps seeding the system
Compare with the other causes of the same sign on this engine: losing coolant (2 causes) · overheating or temperature creeping up · oil leak, oil consumption or rising oil level
Root cause
The A630 oil cooler leaks internally, mixing oil into the coolant circuit (and vice versa). DieselHub calls it the engine's most common and best-documented problem; the cooling system is notoriously hard to decontaminate afterwards. VOQ is nearly blind to it (7 mentions in 1,785 VIN-confirmed complaints) - an owner-maintenance failure, not a complaint-magnet safety item.
Diagnosis
- oil in the degas bottle / coolant on the dipstick = cooler before head gasket on this engine
- plan a full cooling-system decontamination with the replacement - residual oil keeps causing grief
Fixes
replace the oil cooler (oil-filter housing / cooler assembly side of the engine) ()
cooling-system flush + fresh coolant and oil/filter service after the repair ()
Prevalence
common