Have not done a wet/dry compression test. Sorry a noob at all this, could you explain that to me? Replacing the head gaskets, obviously cause they have gone bad or maybe i have been told wrong. Here are the symptoms of my car, maybe you can tell me for sure? Start my car up and let it idle in the drive way and have let it set for at most 25-30 minutes and it never gets over normal running temperature, as soon as I leave the driveway it starts to heat up. Blows cold air, the upper radiator hose is hot after this time, tried replacing the thermostat, added antifreeze thinking maybe I was low. Hope you can tell me its something different!