For those that remember my problem with the 1.7diesel astra (which now has a new engine), I removed the old engine to see if it can be fixed.
I took the head of yesterday and saw this

1

I looks like the piston has foamed up.
It is not just something on it, but this seems to be the piston, as its height is always below that of number 1 piston (this is number 4)

Can t

Looks like it may have got a wee bit warm.

^^Ditto. Looks like its got warm, and melted the crown of the piston.

Never seen it like this though. Could it be some sort of chemical reaction? Would be interesting to take the piston out and try and scrape it off.

I have heard that leaky injectors can causing this type of problem but apart from that i dont realy know, certainly got hot though.