[Nick]

Either I have some weird problem with the cooling system - or I was just dumb enough not to put enough water in the beast. Tell me which...

I noticed earlier today it was puffing steam from a little "X" cross next to the radiator expansion tank . Didn't think much of it, being an E36 newbie 'n all - guessed it was some cunning Germanic engineering at work. Had the car a week so still gettin' used to it.

However, later on... cruising along... the temp starts going up rapidly. Red light came on, so I powered off & pulled over (fast). Hazards on, bonnet up. Very annoying.

A liter or so of water - thankfully had some in the car - was enough to get me off the AYE. After it'd cooled a little, it took fully about 5 - 6 L of water - and then some more. Restarted - no puffing, temp seemed OK, was able to drive another 10 - 15kms with no apparent issues.

So my question - does this sound like some known issue - e.g. is there a valve that's known to fail, letting off steam uncontrollably in the process, or is it a case of dumb-ass driver? There are no obvious leaks from hoses or the radiator itself, and the oil is still OK (not milky). Any ideas?