Moderators: IMOC Moderators, IMOC Committee Members
Have carried out dry compression test today:- 152- 145- 150- 160 Is the next step a combustion leak test? I'm keen to confirm whether the head gasket is on the way out. Are there other tests I can carry out to confirm / rule out failing gasket as the cause?(Testing my patience)(Competent but dull)(3k+ revs with light or more boost) within a relatively short time. Have refilled and bled (radiator and heater core) but I'm getting the same symptoms. There's a lot of air coming out of the system every time I bleed - a lot more than I expect - and a lot of crap too, which I put down to be 20 year old corrosion of the pipes / radiator.(oem) but this doesn't seem heavy enough to confirm. Looks very much like a case of coolant mixing at some point with combustion gasses but I could be wrong (hope I am). (I had photos from when I'd found lots of coolant dripping from the front of engine bay and suspected hose from hell) but he didn't locate any leaks even after pressure testing at 14psi - replaced radiator cap. After a lengthy motorway drive I had a overheat and now the problem repeats itself regularly where revs exceed 3k (eg above 60mph or when pushing on).(Testing my patience)(Competent but dull)- the plastic housing around the filler cap had worn out and stopped forming a seal even after Peter fitted a new filler cap. Replaced that and all good. 
(Testing my patience)(Competent but dull)