Last month my car was overheating when I was coming home after work. I tried turning on the heater to keep it cool, but after driving less than a mile the car would over heat again. I check the fans, check coolant, check oil, and everything was fine. I left the car on the side of the road and came back the next day to remove the thermostat so that I could drive it home. Even with the thermostat off the car at around 5 miles the car would start overheating. Two days ago I drove the car to the dealer to let them diagnose the problem, when I was driving there, at about 1/2 mile the car started overheating, so I stopped the car and let it cool down before driving again. I got it to the dealer and they told me that I have a blown head gasket. I picked the car up yesterday. Drove it around 10miles to my brothers house so that I could try and fix it. I was surprise that the car did not over heat, so I left the car on turn on the A/C to max and left the car running for 30mins. Revving up occasionally to 2000rpm and I could not get the car to overheat. Do you have any idea what the problem may be? Thanks.
It could still be a blown head gasket. The leak can be small enough that the pressure needed for the cooling system to work can leak at times and contamination in the cooling system, rust, etc. Fils the crack long enough to keep the pressure so it does not overheat.