The noise only happens when the fan clutch is engaged. I.E. - stop and go driving, town driving, towing, basically when the engine is hot. From what I understand it is just drag on the belt after shutdown under this condition. Try starting your truck when cold and shutting it back off before it's warm enough to engage the clutch, it shouldn't make the noise. Don't know is this hurts the belt or not but I've got 7000+ miles on my truck and haven't noticed any abnormal wear.

Good Luck,
Sticky

 

Well, this particular time I know for certain that I was not in stop & go and I was not towing anything. Its 10 miles of country road on the way home from work at about 45-60mph, and I was certainly not towing anything that I know of

-daniel

 

On many vehicles the A/C compressor will run in that position. Thats probably why the refigerant is eqaulizing after shut down.

Also, the refrigerant will condense at the coolest part of the system. As your engine cools down in the driveway without the wind blowing through the grill the coolest part of the system starts to warm up, thus the refrigerant migrating.

 

I listed those conditions only as examples of what could cause your engine to run hot and require the fan to be engaged. Basically, anytime the fan is engaged during shutdown the noise will occur. Like I said previously, start your truck cold and shut it back down before it's warm. No rushing noise should occur.

Cheers,
Sticky

 

Yep it sounds like HVAC to me too. When you use your defrost it cycles the A/C unit just as if you had A/C on. Never heard no spool down before that one is new to me. If you hear your turbo AFTER you turn your key off from an idle you probably need to seek a service guy because that is not normal and may be the pre cursor to something major.

 

*confirmed* It only happens when I have the selector on at least 1/2 defrost. When it is anywhere left of 1/2 defrost the rushing sound does not occur.

-daniel

 

Mine has a button for the a/c compressor on the right side of the panel over the heated mirror button. My truck makes the same rushing sound. I sure miss the sound of the turbo spooling down when I shut it off. I'd sometimes shut it down and sit real quiet and still so I could hear it from the driver's seat. As much as I like the Hemi, I sure do miss the Cummins. Not for the mileage or longevity or power or anything other than the Cummins just has character.

On edit, there's the button in my gallery over the gauges.

 

Yes, I've got the same A/C button, but what the system pulls moisture from the air even with the A/C button OFF, IF you've got the dial to even partial defrost mode.

-daniel

 

**** guys, I thought it was just my HEAD RUSHING after racing that Duramax/Power Stroke

 

I agree with you...

Seriously, what your hearing is the freon equalizing in the system. The A/C compressor will run in all most every position. (MAX A/C, A/C, BI-LEVEL, DEF-FLOOR, DEF) All other positions will not run the A/C compressor.

 

Turbo spooldown