I have a 2003 Silverado 5.3L Z71. About a year ago the engine overheated while idleing in a parking lot and later (about 6 months or so) the engine started making a knocking sound...found out the engine block had 2 small cracks in it from this overheating that happened a while back. Anyways, I replaced the engine and ever since the overheating, my fan clutch runs over excessively whenever I run the AC. I have replaced the fan clutch with 3 different ones, and replaced the coolant thermostat, cleaned the condensor, checked the refridgerant...you name it. Nothing seems to be wrong with anything other than that annoying "roaring" comng from the fan clutch when i run the AC. This roaring is affecting the horsepower considerably. Does anyone have any other ideas, that I may have missed? Could it be a bad condensor? Refridgerant pressure is normal. Please help..

 

the fan normally makes a louder noise when the ac is on because the its also needed to turn the clutch on the compressor and when you run the ac it takes away horsepower. its just what it does. i have an 04 4x4 5.3 and the same thing happens so i dont ever really run my ac.

 

I understand it should be louder, but when I first purchased this truck, it didn't do this....i would run the A/C and the fan clutch would engage, but would quickly disengage....I 'm wondering if its something else causing the clutch to "heat" up prematurely, but ifso it deals with the condensor producing more heat than the fan clutch can handle. Are there any "performance" fan clutches that will operate only at higher temps? Can a condensor or radiator be blocked causing a "hot spot" for the fan clutch to react to? Should I have a "Heavy Duty", "super heavy duty", or "severe duty" clutch???

 

if you wanted to. you could always upgrade to electrical fans