Hi everybody I have a BMW 318 E36 convertible which was given too me by my best friends family as he died last year. Me and my mate went to have a look at it and everything was fine gave it a look over test drove I ect ect and ended it buying it. Around a month later if that the pressure in the water system got ridiculously high but didn't come up on dash as over heating, no white smoke, no water or oil convert contamination just a lot of pressure any ways since then we ask a few people what they thought it could be and all came back with HG failuer so we got head looked at the gasket and it looked fine no cacks was a heat spot on first cylinder but nothing major at all. We then send the head off to be pressure tested all ok nothing with it at all so we then got it skimmed it then came back to us and we put all new cam seals valve seals ect ect full top end rebuild and build it all back and running no problems we then took it out for a drive and next thing same happened again! Massive pressure built up but with no symptoms of HG failure only the pressure so he decided to stick it in his garage and fix it when he had enough money by this time he was skint. Not so long after this he was involved in a accident and died and now the car has been given to me and I want to get it back on the road for summer and I can not for the life of my think it was could be so can some one please please help me I'm stuck.