Hi, everybody. I just bought a 1991 F-250 4x4 with a 5.8. When I took it for a test drive, it seemed OK. Later, when I drove it home, about a 20 mile trip, it sounded like it was boiling over when I shut it off. There was a check engine light on, but the temp gauge wasn't reading hot (that I know of). There may have been a little pinging going on and I had a plow on the front. The heater seemed to be putting out heat - so - is it more likely head gaskets or some other problem?

 

Something you can try,
Remove the thermostat and test it in a pot of hot water and see if it opens. If OK, reinstall the thermostat housing without the thermostat ,fill the system and look in the radiator fill opening with the engine idling and see if the coolant is circulating. If it is, would usually confirm that the water pump is working. If you see bubbles coming up from the fill hole it could mean combustion is getting into the cooling system. Sometimes the engine has to be under a load for the combustion to show up.
A radiator pressure test might help confirm that possibility.

 

Thanks. I haven't had much time to look at it since we bought it. I went out there today to look at it. It was almost a gallon low on coolant. I filled it up and started it and didn't see any bubbles (thankyouthankyouthankyouthankyouthankyou) so if I'm really lucky I just have a minor leak somewhere.