Engine Cooling problem
1999 Subaru Outback 4 cyl All Wheel Drive Manual 163000 miles
my outback overheating driving through the mountains in utah and I managed to get it to a town by stopping several times to let it cool down. Once there a shop in the town replaced the radiator and thermostat. But it has overheated twice since then (only a few days), both time while having the A/C on. I turned it off the first time and the temp went back to normal. The second time turned the ac and the car off for a few minutes. Now I don't know what it could be, maybe they didn't replace the thermostat, maybe there is gunk in it, no idea. Any ideas would be helpfull.
Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.
Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.
If the block and pressure test passes check the following: , Pressure test the Rad. Cap, Clogged radiator, air lock in the cooling system, Fan clutch, Radiator electrical fan, collaspe hoses, water pump.