I have a 2001 Blazer ZR2 4x4 with about 80,000 miles on it. The truck runs great, but it's had a strange issue for the past few years. Many times when I accelerate, I'll hear a whirring or whining sound from the front or under the truck, it's fairly loud. As soon as I let my foot off the gas pedal, the sound stops, and I can accelerate as normal. So many times when I accelerate from a stop sign or light, if I hear the sound (which usually starts around10 mph or so), I just quickly let off the gas, the get right on it again and it's fine.

The transmission shifts fine, and the issue hasn't gotten any worse. Transmission fluid is fine and I actually got a transmission flush last year, but that didn't correct it. What could this possibly be?

 

wheel bearing maybe?? i know i have a bearing going bad and i can really hear when i accelerate and not so much when im cruising or braking.

 

I guess it's possible, but when the sound starts, as soon as I quickly let off the gas, and then get back on the gas, it goes away and will not return until I stop again. This sound happens about 25% of the time from a stop. It's very strange.

 

try a couple searches and see what you can come up with, you might find someone whos had a simmilar problem.

 

If it were a wheel bearing it would happen just about all of the time though. It would be a whining/whirring sound...and the faster you go, normally the worse it gets.
I'm at a loss for what it could be though, since it's so random and so little of the time as you said.

 

Does it sound like its coming from right on the other side of the firewall? Something on the intake?

 

[QUOTE=Sisk28;217344]If it were a wheel bearing it would happen just about all of the time though. It would be a whining/whirring sound...and the faster you go, normally the worse it gets.
QUOTE]

i know i have one going bad and its only real noticable on acceleration, other than that you almost cant even hear it.

 

Yeah, it's definitely not fun having to listen to a bad wheel bearing lol. My old civic has 2 go in it, and it sounded like a freight train going down the road lol

 

lol ya it sounds like i running huge super swampers or somethin.