I have almost the same problem i have a 1997 chev 1/2 ton i put a thermostat in it about two weeks ago and its been fine. yesterday i added more antifreeze and the temp started jumping up and down and i have no heat. i went to parts store shut it off an when i started it back it first didnt want to start and then was idioling real ruff the temp never went in the red so if u have any ideas please help
Same punctuation, too.
Both of your posts are too difficult to read so I didn’t go past the first two sentences of either.
You have received some good suggestions, and I have seen head leaks that did not empty the overflow tank. It’s also very possible that you have an air pocket. They are surprisingly hard to get rid of.
It can be helpful to find a steeply sloped driveway or road and leave the car running with the radiator cap off. The air bubble will want to go to the highest point in the cooling system and that is not always the radiator fill although it’s supposed to be, Sometimes the air bubble will make it’s way to the radiator fill if it is the highest point in the cooling system.
Two suggestions. Replace all hoses from the bottom of the radiator to the engine. There often is one from the radiator to a steel tube and another from the tube to the engine. Hoses can collapse internally and block flow.
Take off the oil fill cap while the engine is running. If there is positive pressure, oil blowing out, a breeze coming from the motor, you have an engine problem.