The Problem
2012 BMW with the N20 engine presented with an apparent coolant and oil intermix fault, in other words, the normally green antifreeze was black with oil, and antifreeze had gotten into the engine oil.

Testing confirmed that coolant was being contaminated with engine oil, and the engine oil was noted to have a white foamy mixture on the dipstick and fill cap. Tech diagnosed as a defective engine oil filter housing, the original housing was plastic, BMW has since released an update kit which is constructed of aluminum.

Tech replaced oil filter housing with update kit, engine oil and filter were drained and replaced until the engine oil was free from contamination. Engine was then test run to verify no internal damage. As the vehicle was new to us, and was towed in, testing of the pre-failure condition was not possible.

With the engine oil clear and clean, the next step was to deal with the contamination in the cooling system. Using several containers of solvent, the cooling system was flushed out until the water ran clear, then drained, refilled and protected with the proper coolant. Finally, an extensive road test and engine run test were carried out, to verify completion of the repair.

In Closing
Questions, or if we can be of help in any way with service on your Mini Cooper, BMW, or other European (and now Japanese) import, please contact us. Our team of Service Specialists are here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing”, that’s the Atlantic Motorcar Center way of life.

The Atlantic Motorcar Center Service Team