I was told the whirling noise was caused by my Fan Clutch. The clutch was changed and the noise continued. Only by accident I was standing in front of our Envoy when my wife turned off the engine to get something from the house. The noise continued. I started the engine again and then turned it off. I watch as the fan stopped, but the whirling (jet) noise could be heard through the Air Intake of the Air Filter.
Engine noise after engine is off and fan has stopped turning. What causes this? on 2005 GMC Envoy
What is the trouble you are having other than hearing the engine come to a stop??