Originally Posted by
Galapolis
For what it's worth, I overheated my M54 for what must have been several minutes or so 4 years ago. Needle was about to touch the red zone (or possibly had already touched it, hard to remember).
After that happened I replaced every single piece in the cooling system because I couldn't figure out what was wrong. I think the culprit was the fan unit, which I also replaced, but I never bothered to confirm that. I was just happy that I was able to fix it.
Over 50k miles later the engine is still fine and pulls hard with no issues. I've done track days, autocross, uphill/downhill touge, everything you could imagine.