Reader Question If i have a 1992 Ford explorer and the engine overheats when i use it but the ac works, will i need a new engine or is it fixable at a reasonable price. Thanks Matthew!
If the engine overheats or runs hot ONLY with the a/c on, I would first make sure the radiator is FULL of clean – green coolant. Remove the cap (when the engine is cold) and look inside the radiator neck, the coolant should be at the top. The a/c system puts an extra heat load on the cooling system of the vehicle and a radiator that is low on coolant/antifreeze or full of rust won’t be able to take the extra load.
If the coolant level is full, check the temperature of the radiator – with the engine HOT. Caution, do not burn yourself!!! Start at the top of the radiator in the center and feel it with your hand…it should be very hot, move down the center of the radiator with your hand, it should remain pretty hot. If the bottom of the radiator is MUCH cooler than the top, you have a restriction in the radiator and you probably need to replace the radiator.
Third. Make sure the fan clutch is pulling air across the radiator. With the engine hot and running in park you should be able to put your hand in front of the grill and feel air being sucked into the radiator. With the hood open, engine hot and running you should be able to feel HOT air being pulled from the fan blades over the engine. If you don’t feel this suction, you probably have a bad fan clutch not sucking air across the radiator.
If your vehicle is equipped with an electric fan located near the radiator or condenser in front of the vehicle make sure it is ON when the a/c is on and running.
Here is some more info on the subject Car Overheating
Austin C. Davis