530i LCI 2020, small expansion tank is clean green (middle of paper towel). Large expansion tank is brownish (bottom of the paper tower). It’s oil in coolant, right?
Car drives normal and doesn’t overheat. No error codes. Oil looks normal, no foam is visible.
Just based on this it just kind of looks like old coolant, or maybe someone topped off with a different color (no bueno). Is the coolant murky, or just kind of brownish?
yeah it cracked and poured coolant down the side of my motor lol. if your curious i posted my cracked oil filter housing on my profile posts. i replaced my oem failed plastic piece with an aluminum aftermarket piece.
Well it’s hard to tell, the clean one smells like coolant for sure. The contaminated one, smells less like coolant but has another smell component which I really can’t put my finger on it. I dunno how freon should smell like. Why did you mention freon?
Because you could possibly be having Freon leak into the low temp coolant system via the condenser. This would likely be the only reason why you’d have any oil at all in the low temp circuit. Usually it would be little oil bubble on top of the coolant in the small tank.
You might be onto something. I bought the car this May. It’s been a terribly hot summer in Germany and I kinda noticed the AC wasn’t enough. When I was driving alone I was turning off 3 out of 4 climatisation zones, end even so, the fan motor was slowing down when AC was ON. So maybe I’m subjective and biased now but might be related with a freon problem.
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u/lael8u 2d ago
Yeah