98 tahoe

[tlefmur]

My wife was driving to work and gave me the call. It seems the temp. gauge is on the move (up and down) and the heater is blowing cold air. My first guess was to check the in/out lines for the heater core then to check the coolant level. After some research, It looks like I should check the thermostat, temp. sensor, and intake gasket as well. I've had to do troubleshooting before, but I am a novice and it usually takes me twice as long to locate everything. Any ideas. We are on a limited budget and that's why I do all the work myself.

 

[NOFORDS]

Check the thermostat. Mine is doing this too and I think its a combination of that plus an air lock.