just did compression test...1 cylinder 135 other 3 were below 35 took valve cover off as well as cam shaft. All valves push down and spring back up, not stuck valves Guess its head gasket or rings. hard to believe its rings, as 3 pistons wouldn't go bad at same time. it was running fine then all of a sudden just went haywire. there was bunch of yellow green foam on inside top of valve cover. a lot of that probably comes with not running it long enough after starting.timing belt looks good, but question if it hasnt jumped before because distributor is about out of slot adjustment Thanx tom p