I'm not quite sure what to make of this, hoping it's a common problem. This is for a 2004 Blazer ZR2.

Sometimes when it's hot, and/or I've been sitting in traffic for a few minutes without really moving much, my engine will make a very "airy" or "whirring" sound when accelerating. This will usually last from 0-10 minutes before going back to normal. It may or may not be coupled with a loss in power; it hasn't happened often enough to say forsure. Any thoughts would be appreciated!

Thanks,
Dave

 

Sounds like the engine fan clutch kicked in.

 

Agreed, Sounds like the fan clutch engaged and either needs to remain on to continue cooling the engine or that it is stuck and can not release properly. Check the engine temps that this is occuring at, if they are high then this is entirely normal, if the temps are normal or low, then this is not normal and probably needs to have the fan clutch replaced. This is not a big deal, just might be annoying or a slight decrease in gas mileage (Just means if it were fixed you would probably see a little better gas mileage). Depending on the mileage and if the fan clutch needs replacement or not, I would look into and electric fan install (search the forum for how to's on this/more info) which would free up some lost horsepower and a little miles per gallon. Hope this helps.

 

Thanks for the replies! I'm sure you're right. I guess I should have figured this out, didn't realize the fan clutch soundwould be so noticeable in these trucks; only had it 4 months.