Ok, here's the story....88 Mustang GT, nearly 80k on the odometer, not sure if it's rolled over or not, not a lot of rust on the car, just did head gaskets (toasted one playing with timing. ) and the bores look great, no noticable cylinder ridge. Now, having said all that, I've got a slight problem. When I run the car for around 15-20 minutes, the oil pressure gauge drops to nothing at idle. Oil pressure will come back with RPMs. It will do that 2-3 times, and then the oil pressure will disappear completely. At that time, I get some nasty valve train noise. Now, I live in Phoenix Arizona, and I know my cooling system could use some work. Anyone think that overheating could cause these symptoms? No major leaks, just the usual, oil pan gasket could use replacing. Small water leak at the base of the intake manifold, may also be thermostat housing. No more water in oil, have yet to check plugs...Also, first test drive after getting the car running, cooling system built up waaaaaaaay too much pressure. I think I forgot to completely fill it with water, and boiled what I had in there...Anyways, and ideas, or if anyone's had this problem, let me know. Thanks!