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

Advice needed guys, ive got a 1.0 12v corsa b (w) and it looks like i have oil in the expansion tank, its black not mayo, not 100% sure its head gasket, normal temp and no mayo in oil, i do have some on oil cap but i thinks this is normal.
it has recently had the timing chain replaced, stars first turn, no white smoke out of exhurst, but it does loose some water approx 1pint in 5 weeks.
also water pump not changed, and one of the bolts as threaded just under thermosat housing.

Any advice would be very welcome.

Doesnt sound like HG to me tbh classic sign would be lots of white smoke from exhaust and you would be garunteed to be overheating. My headgasket went in my old car coolant was in the oil loosing all coolant from full expansion tank within 20 minutes lots white smoke and drastic overheating. Could be loosing coolant slightly when you are driving from that dodgy bolt you mentioned. Not to sure what else it could be. Pricer will be along soon lol:)

sounds more like a pin hole leak mate, what condition is your radiator in ? all battered ?

your loss in coolant sounds alot like mine, took me ages to track down all signs of it by trial and error so perhaps read over my project for clues.
ie - hose lines on thermostat.

in the end i put some Radweld into the coolant tank and havnt had any trouble since. coolant holds steady after weeks of reg use.
were as before it would drain half a coolant tank in a day.

Regards Radweld tho i find my use of it to be Messy, again look over my project for pics on everything ive talked about.
in the end tho you gota weigh up your options and if you have exhausted all other means go with the next step. that was my process on it.

Thanks for the advice, will have a good look around, rad is very good, just concerend about the oil in the expansion tank.
what would cause this?
i have been told but not 100% sure, but he said that when the gasket was replaced was instant gasket applied, if not this would cause oil into the water system.
does this sound right?