Whistles At Idle

akkeith · November 27, 2009

Wondering if this is normal or not before I take it into dealer. When my 09 GMC Sierrra 6.0L is at an idle hot or cold it makes a somewhat loud whistling noise kind of a warbling whistle. Then when I give it gas it goes away or at least I can no longer hear it. Any ideas? I live 300mi from dealer so if I don't have to take it in all the better. Thanks for any help.

evanstock · November 27, 2009

I just noticed the same thing on mine today. From searching around this forum, appears to be a common issue which is normal transmission noise. However, I would recommend calling the service department and asking about it, thats what I am going to do. Not too worried about it with the 100K warranty, but it is annoying.

akkeith · November 27, 2009

Very annoying. I thought it sounded like it was coming from the tranny. Thanks

ursandal · November 27, 2009

May not be the same thing but in our Pontiac G8 with the 6.0 the alternator whistles after a cold start. Goes away when you apply some gas/gets warmed up. Supposedly a non-issue, I just figure the engine likes to whistle a tune in the morning.

But then again, my truck (also a 6.0) doesn't whistle and I'm sure they have different alternators between the two vehicles.

evanstock · November 27, 2009

The 'whistle' I heard last night only occured when I idled in drive or reverse, but not in park so i think its the transmission making the noise. I think its the cold weather, it didn't make the noise this morning after a longer warm up.

zroger73 · November 27, 2009

Just about every GM vehicle I've owned has had a "whine/whistle" at idle. My '92 Grand Am, '99 Regal, '00 Cavalier and '09 Silverado. In my case, it always seems to come from the alternator. It's rarely noticeable inside unless a window is down.

Prokopchuk_9 · November 28, 2009

mine has always done it in first gear. 4l80e tranny...always whistles in first. check ur brake boost line too.

akkeith · November 28, 2009

Only makes noise at idle in gear, cold engine or warm. And very noticable with window up. Thanks for all the suggestions.

2500GMC2009 · November 28, 2009

I lubed all pulleys and check the belts (Alternator). No more whistling. My truck only did when cold and if it sat for a couple days without starting.

Rudy35 · November 28, 2009

I lubed all pulleys and check the belts (Alternator). No more whistling. My truck only did when cold and if it sat for a couple days without starting.

How do you lube the pulleys, and what do you use? Thanks.

akkeith · November 29, 2009

I lubed all pulleys and check the belts (Alternator). No more whistling. My truck only did when cold and if it sat for a couple days without starting.

Did it make noise after you accelerated or only idling? It kept making noise even after I drove over 300 miles. And what did you use to lube pullies? Thanks

2500GMC2009 · December 1, 2009

I lubed all pulleys and check the belts (Alternator). No more whistling. My truck only did when cold and if it sat for a couple days without starting.

How do you lube the pulleys, and what do you use? Thanks.

I used white lithium grease with a long wooden Q-tip. I lubed the back of altenator pulley and the back of the pulley where the water pump is. It worked, but was told that after I should not use grease.

Travis E · December 30, 2009

Wondering if this is normal or not before I take it into dealer. When my 09 GMC Sierrra 6.0L is at an idle hot or cold it makes a somewhat loud whistling noise kind of a warbling whistle. Then when I give it gas it goes away or at least I can no longer hear it. Any ideas? I live 300mi from dealer so if I don't have to take it in all the better. Thanks for any help.

Same problem with mine. Had it back to dealership 3 times for it. The re-routed the electrical line up on the passengerside firewall. It was moved from firewall to black metal brace. They insulated behind tie fuse and straped it to the brace. The noise is still there but not near as loud and annoying. Hope this helps.