Rep Power: 0

Hey guys, got a little problem here. Last week there was a rainstorm, i start up my car and start driving home. I turn on my heat to highest setting cuz it was cold. No heat. I noticed my temp gauge rising until it was all the wall past the H so i got afraid and pulled over. I tried AC and it worked fine but still no heat. I thought it was low on coolant, i added some but to no avail. I was going to replace thermostat until it ran fine the next morning,no temp gauge problems, and heat worked fine. Today it was raining again so i went for a drive,same temp gauge going high and no heat also.I then replaced thermostat but problem persists.

Was wondering whats up? If heat works tar morning ill let you know but i just want to find this out quickly because i am planning on selling it. Thanx guys, any info is appreciated.

 
Rep Power: 518

Head gasket!

What's the radiator and overflow bottle doing?