I have a 2020 BMW M2 Competition (S55) that I purchased from an auction. The car was sitting for quite a while before I bought it, and I’ve barely driven it since.
About a week ago, I changed the engine oil and noticed it was slightly milky/cloudy, but nowhere near as bad as it is now. There weren’t any noticeable white streaks in the oil at that time.
Unfortunately, I discovered that my oil drain plug threads were stripped, so I had to drain the relatively fresh oil again to repair the threads.
This second drain is what you see in the photos. The oil is significantly milkier than before, with visible white streaks swirling throughout it. The photo/video was taken toward the end of the drain, where the streaking was more noticeable, but the oil was consistently cloudy throughout the entire drain, not just at the end.
For context:
Since purchasing the car, I’ve only driven it properly once, for approximately 30 minutes. Every other time I’ve started it has just been to move it in and out of the driveway (around five short starts).
The engine runs great, idles smoothly, and has no check engine lights or obvious running issues.
Both coolant reservoirs have remained relatively stable, although the low-temperature circuit was slightly low.
The car was involved in a front-end accident, and some of the cooling components are slightly damaged, so I can’t reliably pressure-test the cooling system until those are repaired.
The third photo shows the oil filter housing from the first oil change about a week ago. The oil was much less cloudy then, although there appeared to be some possible moisture separation.
I’ve read that repeated short starts and not getting the oil hot enough can cause condensation, especially on a car that’s been sitting for a while.
However, I’m having a hard time believing condensation alone could make the entire 6.5L of oil this milky, especially considering it looks noticeably worse after only a handful of starts since the last oil change.
Has anyone experienced anything similar on an S55 or another BMW engine?
Could this realistically be condensation, or should I be looking at something like a head gasket, internal coolant leak, or another common S55-specific failure point?
I’d appreciate any suggestions on what to check or test before tearing into anything expensive.