Whistle Noise From Alternator Or Throttle Body

General Jackson · November 6, 2007

I pulled the following TSB's (see below) and already replaced my PCV valve and put a new alternator in my 01' Tahoe. I'm still getting the whistle noise and can't figure it out! Does anyone have any other suggestions as to what could be causing the whistle noise? I noticed an increase in the sound when I pushed up on the window buttons, which increased the power consumption in the truck. It seems to me that it is an electrical issue, but the whistle gets louder and softer with the RPM's or if I push up the on window buttons.

Thank you for any help you can give me.

Andrew

TSB #3086 -- WHISTLE NOISE FROM THE THROTTLE BODY AREA ON LIGHT THROTTLE

ACCELERATION ON VEHICLES WITH GEN III ENGINES AND ELECTRONIC THROTTLE. *TT

(NHTSA ID #10009512, JANUARY 01 2004)

a.. TSB #00969A -- ENGINE WHISTLE NOISE. *TT (NHTSA ID #10005469, JANUARY 01

2004)

wgabert · November 7, 2007

I have the same noise. I am sure it is electrical, and seems to be originating somewhere in the dash. even with the radio off it is there. hope we can find out what it is.

warren

General Jackson · November 9, 2007

I have the same noise. I am sure it is electrical, and seems to be originating somewhere in the dash. even with the radio off it is there. hope we can find out what it is.

warren

Yeah, it does it with the radio off. Mine is really starting to make me crazy. I have replaced the PCV valve twice now and nothing changed. I cleaned the TB very well and zero has changed. I am considering that maybe it's the main drive belt tensioner. I noticed a slight improvement after I replaced the alternator. But, I don't think it has anything to do with the alternator. Maybe it's because my tensioner was kind of tight for a long of enough period to make the noise go away for a few minutes. That being said -- It might explain why our whistle noise increases and decrease when theire is more or less strain on the alternator. It might be because the alternator strains itself, which causes a larger strain on the belt tensioner that it is connected to. Does that make sense? I think I'm going to replace the belt tensioner tomorrow to see if that helps anything. I'll keep you posted. Are there any techs out there that can help us?!

Questions: I have an 01' and don't seem to be able to locate the IAC valve. Is it possible that I don't have an IAC valve? The diagram in the Haynes manual says it is on the side of the TB on the early V8 models. If I don't have it there on the side, then where is it located?

Thanks you

General Jackson · November 9, 2007

I have the same noise. I am sure it is electrical, and seems to be originating somewhere in the dash. even with the radio off it is there. hope we can find out what it is.

warren

Yeah, it does it with the radio off. Mine is really starting to make me crazy. I have replaced the PCV valve twice now and nothing changed. I cleaned the TB very well and zero has changed. I am considering that maybe it's the main drive belt tensioner. I noticed a slight improvement after I replaced the alternator. But, I don't think it has anything to do with the alternator. Maybe it's because my tensioner was kind of tight for a long of enough period to make the noise go away for a few minutes. That being said -- It might explain why our whistle noise increases and decrease when theire is more or less strain on the alternator. It might be because the alternator strains itself, which causes a larger strain on the belt tensioner that it is connected to. Does that make sense? I think I'm going to replace the belt tensioner tomorrow to see if that helps anything. I'll keep you posted. Are there any techs out there that can help us?!

Questions: I have an 01' and don't seem to be able to locate the IAC valve. Is it possible that I don't have an IAC valve? The diagram in the Haynes manual says it is on the side of the TB on the early V8 models. If I don't have it there on the side, then where is it located?

Thanks you

I replaced the main drive belt tensioner and the indle pulley assembly. I still have the whistle noise!!!