'99 S-10... new sound under the hood

TopPost Does it sound like a airplane taking off? If it does then it is your fan clutch ...Take your belt off and start the truck...Rev it up and if the noise is gone its your fan clutch.. Steve C

'99 S-10... new sound under the hood Group: alt.trucks.chevy Date: Tue, Feb 10, 2004, 8:05pm (CST+1) From: snipped-for-privacy@99main.com (rebek) I've been trying to place a new sound that shows up when I rev the engine while standing still or am driving along at usual rpm's. It's another sound that almost suggests a blowing, or somehow some other source of rpm. It seems to lag the engine rpms and takes longer to drop down than the engine. Temperature stays fine with no change from before the noise, it doesn't putt on the way down to suggest an exhaust leak and the block/ exhaust manifold face is clean. It idles just fine. I've never heard of a fan clutch doing something like that, but could it?

Hi!

Just to second that, it's your fan. My '03 does the same thing. I think it sounds way cool, even if does kill fuel economy or performance. Makes it sound "big" and "serious" for a few moments anyway... :-)

William The Guesser

It is a normal sound. It is a thermal fan clutch and not a non thermal, so it will make that noise for about a minute of driving.

If he does take his belt off, of course it wont make noise because the fan won't spin at all seeing its only one drive belt.

Very good that is the purpose of taking off the belt...If the noise persists then he has problems elsewheres Steve c

My 99 Blazer does that too. It has done it since I bought it new. I don't worry about it. It goes away shortly after startup. If I had to guess it sounds like intake air is being restricted or redirected from another location, like near the exhaust manifold where it is warmer. Then it switches back to a "normal" air flow. It has not affected the driving at all so I don't worry about it. Mike