Coolant header tank

[rrblue]

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.

[rrblue]

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.

[johnny]

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

[williamt73]

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.