I opened the bonnet to my Astra 1.7 DTi LS on a 2003 plate (No more warranty :-( ) and found grey matter oozing out of the water expansion bottle. After opening the bottle top I realized it was full with the stuff, I took out the bottle and emptied it, reconnected and it started filling up again. The engine starts and runs fine, there is no water in the engine oil at all however the level is decreasing. The oil in the water isn't just a streaking it is a high density gunk ! If it was the head gasket I would have expected water mixed with the engine oil or the car to over heat or the water level to go down. Is there any place else other than the head gasket where the oil can seep in to the water system? Thanks in advance. AS