So after taking my BMW to a local INDY he replaced the oil cooler and oil filter housing did 3 flushes. After I drove it for 130 miles and when i got back home i opened the coolant reservoir and it had chocolate looking fluid again. Spoke to the indy mechanic and he said to keep doing coolant flushes. After reading up on this problem many mechanics were using non sudsing dishwasher detergent. Is it safe? Also could the oil be getting in from the trans cooler?


Oil in radiator fluid after draining from radiator. 5 flushes and Red Devil used.

This is white exhaust from my tail pipe.

This is the OFH that the indy replaced instead of just putting a new gasket on and a markup of 50%, Predators.

 

I've done two different N52's oil cooler and oil filer housing gaskets. Neither was in horrible shape, but they were clearly done. After the job, I saw a very slight sheen of oil in the reservoir after the gasket change. Like what you might see if you dropped one drop of oil on a cup of water. Initially I was alarmed, but eventually settled on this being incidental contamination from the gasket change. Never was is so bad it was milkshake looking. But, I suppose that could be worse depending on how bad the gasket was ahead of time. I would proceed with flushes until it goes away and after a few, if it doesn't then maybe something else is wrong.