the Unforgiven
Member
I've got a pump engine that is giving me fits. It runs real nice, might go twenty minutes, might go four hours, runs nice and cool but then the temperature gauge swings way up, then way down, then right back up and hits the peg to kill the engine. The needle on the gauge moves fast too, swings up and down like the needle on a tach. Start it right back up, hold the safety switch for about ten seconds and it's cooling off, throw the clutch back in and pull the throttle out and the temp goes right back down, but it will do this trick again, just a matter of how long. 454 on lp, drilled a hole in the thermostat, new big radiator, water pump is moving coolant like it should, it isn't throwing anything out of the overflow after the initial burp if you fill it to the brim when it's cold. The only time it will keep running is if I put in a gutted thermostat. Tried two different gauges and thermostats, absolutly no difference. Starting to wonder about a headgasket leaking a little but I can't understand how it could build enough of an air pocket near the thermostat and release enough of it all at once to act crazy. Been fooling with it for a week now, only have a couple handfulls of hair left to pull. Any suggestions?