The engine starts normal, I let it warm up, I have heat, after driving for about 10-15 minutes I lose heat and then shortly after the temp gages rapidly climbs to H. After about 10 seconds the temp drops back to normal amd I regain heat. Thermostat? Also, I hear a gurgling sound when I turn the engine off, I think it is coolant boiling? Flush the system? Thanks for your help!
Drain the coolant. Remove the thermostat, and replace it with a new one of the correct temp range. Remove the radiator, turn it upside down. Wrap a rag around a hose, and insert it into the lower resevoir. turn on the water full blast to back flush the radiator. When most of the rust and crud is washed out of the upper radiator resevior, turn off the water and drain the radiator. Take a flash light and peer into the upper resevoir, are there still chuncks of rust clogging the core? If yes take it to a shop and have the core rodded out. Otherwise, replace the radiator and the hoses. Add coolant, but be sure you use anti-freeze anti-boil to prevent rust and avoid this problem in the future.
Thanks for the help! I’ll try that.
I don’t think the engine can overheat and cool back down in 10 seconds.
I think a bad ground connection is making your gauge go wacky and and your blower motor stop intermittently.
If it was an electical problem it would not happen consistently as is described. A bad ground can cause some odd instrument readings, but it will also cause problems with lights, horn, starting ect. the gurgling sound is probably not part of the problem, it is the sound of coolant being drawn back into the cooling system from the overflow tank when the engine begins to cool. If the thermostat is sticking or clogged, once it opens the temp will drop dramatically and quickly back to normal. A collapsed lower hose will cut off the flow of coolant sometimes too, and cause similar problems.
This is common if there is trapped air. Hot air will not open the thermostat, only hot coolant. I’ve seen this many times with air trapped in the cooling system.