Hi all,

Hope you can help. I was at a track day on saturday and had a few spins. later in the day i noticed my engine temps were up a bit. I took the cap off my expansion tank and was greated by this :


goo

It had the consistency of hot chocolate but looked like something else entirely . Anyway I cut my track session short, took the car home and drain the system. I couldn't see any trace of oily residue in the coolant (my initial thought was head gasket?). I also drained the oil and nothing seemed untoward there either. I flushed the coolant system through, and took the car out for a run. Now obviously I can't replicate the abuse the car gets on the track but after 45 minutes of driving I found no evidence of hot chocolate syndrome!

Any ideas? I thought maybe the spin dislodged some cr*p in the coolant system?

TIA

If it's oiley to the touch then it's oil (fromt feed to head via head-gasket). Sometimes when you drain it it sticks to the head, block etc and doesn't appear in the drained water... but it'd reapear when you refill and run it.

More likely (if it's not oiley) is that it's rust from the block that got stired up with hard running. Treat it with a good quality coolant flush then see how it goes.

adrian

[Edited on 11/8/10 by adithorp]

It wasn't oily to touch, i'm inclined to agree with you. I flushed the system through a few times (front ways and back)

Thanks for the recomendations!

Run it for a few miles with good coolant flush (I'd recommend Forte if you can get)added. It should dissolve the contamination and hold it in suspention. Then drain and hose through and refill. If all clear, refill with with anti-freeze and possibly Forte cooling system conditioner.

Mmm it could be the wax from the thermostat possibly.

I pulled out the thermostat and tested it. Seems to working fine. I guess if the wax had leaked it wouldn't open properly?

You have done the engine a huge favour, by thrashing the living daylights out of it you have given it a good clear out.
The cooling system should work even better now.

I have heard about some organic coolants used in BMW & Mini turning into a horrible foul smelly brown goo if contaminated.

Many years ago, one of my dads bass developed a header tank FULL of algae. Anything like that maybe?

I would think algae might smell a bit. This didn't smell at all. It didn't look to appetising though