Question, please o learned forum, my GMC has recently lost water into the sump, head gasket changed, which the old looked suspect across an oil/ waterway . Fully flushed, 20 miles later, same problem, runs perfect , no pressurisation in cooling system beyond normal.Did a cylinder leakage test at both TDC and BDC , no air escaping into cooling system there, so now stumped :banghead:
Before I purchased had sat for a few years, so wondering if the head has split/ cracked between ways to allow oil to sump, thought I would get the head crack tested or x rayed but told by two local companies this is no longer done ?
Is there anything I have missed or could do :thanx: