When idling for 10 or more minutes, my 01 Silverado has recently experienced a radiator fan noise (like a supercharger noise!). I also noticed that the temperature gauge rises to about 230 degrees. Once I accelerate and drive for a while, the temp settles back to around 200 degrees but the fan noise continues. There also is a loss of power big time.

I have changed the t stat and dexcool coolant about a month ago but this didn't solve either problem.

Any ideas?

Jeff

 

your clutch fan might be going out..go out and wiggle the fan back and forth..

 

It doesn't move front to back and when I free-spin it, it has a little resistance. No signs of bearing failure but the noise sounds like a jet engine or supercharger.

 

The fan clutch has a heat sensitive grease in it that causes the clutch to "lock-up" and the fan runs with out the normal slippage. Resulting in a lot more noise and robbing a lot of power. This is a safety devise to bring more air across the radiator when needed. As the temp comes down it will revert back to its normal slippage.