Can someone tell me what might be wrong ? My car blew the rear head seal and all the water came out so it over heated. I have a A13 head that was cleaned,new valve seals and ready to be put on. I swapped the A12 head for the A13 head and used a A13 head gasket. I left the A12 intake and exhaust manifold. I did change the studs around so the intake could fit. I calibrated the valves and started the car. No problem, car running smooth with no smoke and charging because that what started it all,alt froze and broke the belt. Well anyway, the car is charging and running smooth, then it started tapping after awhile. I turned it off and recalibrated the engine while hot. I noticed that it was dry. I turned it back on without the valve cover and bang...NO LUBRICATION... oil is full and added some washers to the oil pump spring for more lubrication. Didn't work. My oil light turns off when started but no lubrication on top. I also took off the valve rocker arm shaft and it's all nice and clean. The correct bolt is in where the lubrication goes up !!! What can it be ? Please help. I'm getting frustrated with my car.Don't want to swap engines yet until this one is running :(