Gunk in filler cap

[Motorhole]

Just checked out a donor car for m52 conversion. Runs well, pulls well, doesn't overheat, fan came on fine, fairly low mileage, starts first turn etc. However there was a lot of gunk in the filler cap and water droplets after running it for a while. I'm quite sure this is just condensation as it hasn't moved for a while, just after a 2nd opinion. No oil in coolant, no gunk on dipstick and doesn't 'smell' hot when running.[/img]

[daimlerman]

Did you quiz the previous/present owner as to usage?

As you are aware,lots of short trips will allow a build up of rubbish in the top of the engine.A decent run out at sensible engine speeds will tell you if the head is damaged.In my limited experience with my M50,they handle abuse to the cooling system very well!

[macas]

I have bought an m52 engine and a whole e36 2.8 car and both had gunk in the filler cap,and like you have wondered if something more serious was going on but both were fine,if it doesnt overheat and everything runs as normal dont worry!!

[Gert_8]

Gunk was usually due to short runs, but my local garage informed me that detergents in oils these days can also cause this, and its not something to be overly concerned about. Especially if all the other signals (clean dipper, no oil in coolant) seem fine?...

[Motorhole]

Cheers guys. Will most likely be pickingbit up tomorrow then!