53,03 plate Astra 2.2 SRI.
Loosing a small amount of coolant for months was never able to source a leak (approx 1 cm a week down on the header tank fill line).
Went to start car the other day and it was as if I had a flat battery on the first turnover, stopped, tried again and engine fired, accompanied by a nice cloud of white efflux from the exhaust drove to work and as engine warmed no smoke. Stopped at work immediately restarted car - no problem started as normal, time to go home eight hours later and same issue on first turnover slow and rough second time car starts ok but with white smoke from exhaust which cleared after 10 mins. Car runs fine once started and better when warm, no smoke during normal driving once engine warmed up. Checked engine bay and have lost a third of the coolant from the header tank (in 18 miles) I am suspecting a head gasket failure,(are these engines prone to this ?) but could it just be the inlet manifold gasket ? or would people suspect something more sinister than a head gasket. I am in the quandry of getting it fixed or trading it in !! engine has not overheated and no sign of mayo in the oil, or oil in the header tank.
Had a quote (£550)which includes getting the timing chain guides, sprockets and oil feeder replaced at the same time (the vauxhall mod pack), I am told this is a good idea as these engines apparently can eat timing chains,head skimmed (if required) new bolts car etc has done 40,000 and to be honest I just really like this car, but I have had experience of head gasket failure and replacement before that led to months of grief (not on this car)
Any help or advice would be much appreciated