So I have an F10 M5. Coolant has NEVER been changed since it came from the factory (Euro Delivery).
Had the heat protection recall done. Got a low coolant light, and found it was leaking at the hoses (and ate through part of the cooling mat). Topped up with some distilled water and crimped the hoses.
Now, here's the really odd thing. The main radiator coolant isn't blue/green. It's a yellow orange color (at least that's what it seemed like when I saw the leakage)! The ECU/Intercooler coolant IS blue/green. I'm perplexed. I've been googling around for what a yellow/orange coolant is, and I can't find any info on it at all. Does anyone else have this or have any clue?
I'm definitely not the only one, as it's the same as seen in this video with the yellow stains (but not as bad):