1993 Toyota Camry Overheating When Ac Is On

[gus1963]

HI, I have a toyota camry that keeps overheating ONLY when the AC is on. my husband has chanded the water pump, the thermostat, hoses, checked the engine cap for milky substance (which i'm told would mean oil and water mix, or something to that effect) but it still over heats when we run the air. if you turn off the air after it cools and sometimes before it gets too hot, then it doesn't overheat. can ANYONE tell me what else i can check?

[inafogg]

is the cooling fan working there should be 2 fans one runs by engine temp. the other should come on when a/c is turned on

[gus1963]

thanks a million for answering, my husband just told me that he DIDN'T CHANGE the thermostat, he read in the manual that if the hose is NOT hot but the engine is, the the thermostat is stuck in a closed position, preventing the coolant from inside the engine from escaping to the radiator. after he replaces it, if it works i'll post it for other's. thanks again for answering.

[Mike Gerber]

Originally Posted by inafogg

is the cooling fan working there should be 2 fans one runs by engine temp. the other should come on when a/c is turned on

Actually both fans should be running when the A/C is on. Make sure they are both turning on when the A/C is on.

You don't say how many miles are on the car, but 2 additional things come to mind. The first one is a cheapie to try; simply change the radiator cap. If it's no longer holding the proper pressure, the cooling system will not take as much heat and be able to dissipate it. The pressure created by the proper cap raises the boiling point of the coolant mixture. I would just change it since it's very cheap. If that doesn't solve the problem, then I would have to look at the radiator itself. Is there an obstruction such as dirt and leaves restricking the airflow through the radiator. If so, clean it out and see if the car still overheats when the A/C is on. If no obstruction, then the problem figures to be with the radiator itself. Take it out of the car and take it to a radiator shop to have it flow tested. It may have restricked flow inside of it and can no longert handle the added heat created by the A/C being on. If the car has many miles on it and not a lot of cooling system maintainance, then it's probably time to just replace it.

Mike

[gus1963]

believe it or not my car only has ONE fan. the radiator cap is new.

[inafogg]

i'm not positive but i believe there should be 2. does it look like one is missing or is there a place in front of radiator(engine side)where one should be. how long have u owned car?

[gus1963]

no there's no place for another fan, i've had the car for over 6 years now and have NEVER had any problem until now. oh, and the thermostat didn't work (the new one we just bought). there's some type of sensor we're supose to find. this is a v6 xle, if that helps anyone trying to help me. thanks in advance.

[davemac2]

You have the hydraulic fan on the '93 XLE I am assuming, driven by the power steering pump. Make sure your PS fluid is ok. It should be turning all the time pretty well and go to high speed when A/C is on or the engine Temp requires it. Is it full speed when this overheat occurs? Full speed will move a lot of air. make sure there is nothing blocking the radiator or condenser such as a bag that got sucked in or something. The temp sensor for the fan control is mounted on the thermostat outlet below the alternator. The A/C condenser cooling will put an extra load on the rad so if your engine cooling system is marginal, then using the A/C can put it over the edge. When not running the A/C with the engine warmed up (ie. driven for 15 min at least), what does the temp gauge on the instrument panel read?

Did your husband flush the rad? Are you sure the rad has good flow? When the engine is first warmed up from a cold start, you should be able to remove the coolant cap right near the engine and observe the coolant there initially to see if it is flowing. Are you sure there is sufficient coolant in the system with no air blockage? Did your husband fill the system with the front end raised or with the car parked on a good steep hill?

dave mc

[Brian R.]

If flushing the engine and radiator, and changing the radiator cap has no effect, I would replace the water pump-along with the other belts and seals that are accessible during this change. Water pumps are known to corrode and become less efficient with age if the coolant is not kept really fresh over the life of the engine.

[gus1963]

did everything everyone has suggested, soooo he's going to go out today and get a NEW radiator. runaround , i really hope this works, we don't know what else it could be. thanks again to EVERYONE whose been offering help.