Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

I flushed the coolant this weekend and all looked pretty good. Clear and pink.

However, I noticed the header tank was lined with a thick rubbery/oily deposit which I managed to clean out with a toothbrush and lots of petrol.

Any thoughts on where this might have come from. I suspect that someone in the past has mixed coolant types or there may have been a head gasket problem in the past.

Coolant seems to be flowing freely now.

The other possible cause that occurs to me is that the redidue is from the degradation of the various rubber hoses over the years.

Thoughts please.

It could be any number of containments that have got in through the years, I wouldn't worry to much about it unless it comes back quickly

The car has had oil mixing with water in its previous life. That could be from a failed head gasket - or more commonly if it is a 1.0 or 1.2 16v - from a failed timing chain gasket. It takes a long time to flush out all of the oily muck.