Coolant Leaks

[dkl]

Originally Posted by jdstrickland

The aux fan is used in conjunction with the AC, there is also an aux pump that helps keep the cabin warm if you shut the engine off is a place such as the drive-thru lane.

This is not the case with my car. The aux fan doesn't necessarily come on with the AC and my AC works perfectly. I do usually see/hear the aux fan running after shutting off the car after running it "hard". However, I haven't heard it (the aux fan) running recently, if I recall - it could also be due to the colder than normal weather that we've been experiencing recently

[X5chemist]

Originally Posted by Fifty150hs

That's interesting as that is only 1 Bar and the cap is supposed to hold up to 2 Bar. One of the reasons some think the M54 cooling systems like to self destruct.

The test procedure is probably set for cool or warm pipes. At higher temps, the 2 bar cap and seals will hold. I run a 1.5 bar cap on mine. It does loose a little coolant in hot weather. I keep it topped off. It's only a small amount of water add to keep it topped off.