I have a 2001 cadillac sts and it only overheats when the ac is on why?
The AC sheds the heat from the passenger compartment through the condenser (which looks like a second radiator), which is in front of the engine's radiator. That “preheats” the air that pulls heat from that radiator.
If the radiator has all it can do to shed the engine's heat using the air that is at ambient temperature, preheating that air will push it over the line into overheating.
Additionally, the AC removes the heat in the passenger compartment through the work that the AC compressor does. The AC compressor gets that power to do that work from the engine. This in turn causes the engine to work harder, creating more heat to get rid of than when the AC is off.
If the coolant is old, replace it.
Ensure the belt is tight enough on the water pump.
On many cars there is an electri fan that comes on with the AC, mounted in front of the condenser. If you have this, ensure it is operating.
Jun 24, 2010 |
2001 Cadillac Sts