This is happening on our 2005 Tahoe, not our Dmax, but they're basically the same inside.

When the Tahoe is ilding, there's a noise in the cab that sounds like something metal rubbing. At first, I thought that it was a A/C clutch, because it would kind of go on and off when you'd turn the A/C on and off. Now, I've decided that it's the expansion valve in the evaporator in the cab, because it slowly tapers off, and then goes away when you turn off the A/C.

Has anyone else noticed this? It's cold now, so it's hard to tell if there's some bigger problem with the A/C. I'm sure that if's there's something that's wrong, it will show up in the summer, and we'll still be under warranty. However, if there's some known problem with this, I'm *****in' now to get it on my record...

CADman_ks

Yes, if it is real quiet you can hear a noise, kind of like air escaping... I think there is a TSB... Be back in a minute...

HVAC Hiss Noise with AC On - kw GMT800 GMT805 GMT806 GMT820 GMT830 idle blower compressor line hose #PI02148 - (Jun 21, 2004)

HVAC Hiss Noise with AC On

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When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1528380&pubid=564&evc=sm#ss1-1528380">Condition/Concern:

Customers may comment of a hiss noise coming from the dash area with the A/C on. The noise can come and go or change/ intensity depending on A/C system loads (outside temp, engine RPMs, humidity, etc.)

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1528380&pubid=564&evc=sm#ss2-1528380">Recommendation/Instructions:

The noise is normally only heard while stopped with blower on low and radio off. The noise is coming from the A/C orifice tube and is normal. No repairs should be made.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1528380&pubid=564&evc=sm#ss3-1528380">Models:

(03-04 Chevrolet All Full Size Trucks and Utilities) and (03-04 GMC All Full Size Trucks and Utilities) and (03-04 Cadillac All Full Size Utilities)

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Thanks for the reply. That's what I was pretty sure that it was. I just wanted to make sure that there wasn't something wrong with the expansion valve that may show up at a later date!!!


Thanks again,

Darrin