Hi, i've heard other blazers, and even silverado's do this i just don't know what it is or if its a problem. Sometimes when i start my blazer or even my 98 350 silverado i get a louder almost air sound in the engine. Once i get up to about 20 mph or so it always goes away and seems to do this when the engine is cold. Is this even a big deal or problem? thanks

 

It might be due to the cooling fan clutch going bad, causing the fan to come on when it's not needed.

 

It's the clutch on the fan. I believe that when the vehicle has been sitting for a few hours, the clutch engages. It's fairly common, and also "normal".

 

I don't know why i couldn't think of that, but the clutch fan makes perfect sense. Thanks for the help