My IROC with a 5.7 overheats if i dont have both fans on, i changed the thermo to a 160 and put a new cap on the rad. but it still will overheat if the sec a/c fan is not on, i have the dual heavy duty fan set up but i just cant figure it out if any one can help please do
thanx

 

Both fans should come on automatically when the engine gets hot enough. If not you may have a temp sensor problem or the fans aren't wired properly.

 

another thing i have heard, just heard, is if you do put to low of a thermo in your car, it may not trigger the computer to turn the fans on. Plus now your coolant is flowing through your engine a lot more often to keep it at that temp, thus, making it hotter, faster.

 

Also make sure the Air Dam is under the car.

 

DOES THE AIR DAM REALLY MAKE A BIG DIFFERENCE?

 

Yes it does, take a look at the restricted openings on the Front of the 3rd gen cars. At city & highway speeds your largest air supply for cooling comes from under the car from the Air Dam. Or if you want to say it not necessary, remenber GM did NOT add anything that they could have deleted and saved money.