Maybe a head gasket

Devil Horse · Sep 1, 2022

Got a 96 gt with the 4.6l 2v
A little while ago my thermostat decided to quit opening and my engine overheated. It got to 260°f before I was able to get to a safe place to stop where I wouldn't get hit by traffic. I replaced the thermostat and have even checked to make sure it is working as it should, but it's still running a little hot. It hasn't gotten over 220-230 but takes no time at all heating up ones you get it going down the road.
I don't have a way to do a block test and the nearest shop is to far to drive it as it is setting. Old and water is NOT mixing but I'm not so sure it hasn't blown a head gasket on the exhaust side.
Is there a way to check for a blow head gasket without a block check kit (test for exhaust gas in the coolant), or is that going to be the only way?

96blak54 · Sep 2, 2022

Its possible with the thermostat change, an air pocket got in the system.

Remove radiator tank cap and start massaging the upper return hose. Do this with a cold start engine while the front end is raised.

Venompower · Sep 2, 2022

Devil Horse said:
Got a 96 gt with the 4.6l 2v
A little while ago my thermostat decided to quit opening and my engine overheated. It got to 260°f before I was able to get to a safe place to stop where I wouldn't get hit by traffic. I replaced the thermostat and have even checked to make sure it is working as it should, but it's still running a little hot. It hasn't gotten over 220-230 but takes no time at all heating up ones you get it going down the road.
I don't have a way to do a block test and the nearest shop is to far to drive it as it is setting. Old and water is NOT mixing but I'm not so sure it hasn't blown a head gasket on the exhaust side.
Is there a way to check for a blow head gasket without a block check kit (test for exhaust gas in the coolant), or is that going to be the only way?

I'm with 96blak54 if it were head gasket you would either see milkshake oil, or you would see the coolant burning off in the exhaust. My guess would be air pocket if the oil and exhaust look normal.

Devil Horse · Sep 2, 2022

Drove it today when I got home from work just to move it to do some yard work. It started cold with a high idle (1800 to 2000). Decided to take it down the road to see if it cleared up and it kept cutting back like it was trying to stall out. Had to keep above 2k just to keep running okay but would still have a hiccup here and there.
It about felt like it wasn't getting good compression or not firing good (no codes).

I'll try and check for the air bubble this weekend.