buzz, buzz just off idle

melbertbloosfan · February 25, 2004

'Kay, want to check and see if this is a common problem or what.

Truck in sig (21000 miles now) has a bad "buzz" that seems to be coming from the middle dash area when accelerating from a stop. Does NOT happen when you idle away but DOES happen when you lightly tip-in the accelerator pedal, say to 800-900 rpm.

The dash buzzes very loudly.

Anyone else have this? Happens in cold/warm/hot weather upon startup and warmed up. IOW always when I step lightly away from a dead stop. Now, if I step a lil harder, no buzz!

Thoughts on where to steer my clueless dealer when I have to take this in?

Driveshaft? Motor (does not happen when I lightly rev in park, tho)? Tranny?

Pretty much has happened for the last year or so.

Thanks for looking!

Mule · February 25, 2004

Believe it our not, the harmonic buzz coiuld be coming from the exhaust. Happened to me, exactly like you said. The noise travels through the system and appears to be right in front of you. Look for any loose bolts, loose heat shields, or manifold.

There are some other threads with similar problems/soluitions.

Shaggnasty · February 25, 2004

check your Vortec cover on top of your engine...it

is not the cause of the noise, but can rattle and make it

worse. Take it off entirely and see if that helps. If it does,

you can grease the plastic tabs that secure it to the engine

(although it did not work for me...I left it off).

I always thought the 800-1000 rpm "buzz" was transmission related.

melbertbloosfan · February 25, 2004

See, that's why this is the best board on the net!!!

Two good suggestions (which I would've never thought of on my own) that just may save me a trip to the dealer where I might have to look at all those shiny new Tahoe$.

Will try them both, guys, thanks!

COZWV · February 26, 2004

My 2002 has the same exact noise in the dash. sounds like it is coming from behind the insturment panel. I'm planning on trying to find it when the weather warms up.

COZ

jsmith555 · February 26, 2004

Go and search back a few pages and look for a post "Vibration from Exhaust."

I still have it in mine. Tried the "greasing the Vortec cover tabs and looked at everything underneath. The dealership has had it twice already and still no fix.

Patiently awaiting a resolution.

Jackson

melbertbloosfan · February 26, 2004

My 2002 has the same exact noise in the dash. sounds like it is coming from behind the insturment panel. I'm planning on trying to find it when the weather warms up.

COZ

Yeah, really sounds like it is coming from just behind the dash. Does not sound like an exhaust vibration as it really, really sounds like it is coming from the dash area.

But, will try to look around this weekend under the truck for loose exhaust pieces and will check the vortec cover.

The good (?) thing about this buzz is that there is no way in he11 that the dealer will be able to "could not duplicate" me. I mean this thing is LOUD and one drive around the lot will verify this!

Mule · February 26, 2004

My sound did not sound like exhaust and that it was in the dash like yours. I swapped to Banks headers and exhaust, and it was gone. After 4 years, it is starting to come back. It isn't the exhaust, but the harmonic vibration from something loose in the exhaust that makes the dash vibrate.

But that is what happened to me. All of the other suggestions may be the soution, too. I know on older tucks, the speedometer cable would need lubed and that is the same sound, but newer trucks don't have the cable.

Let us know what you find.

Import Hater · February 26, 2004

I have a sound like this. I only get it right after a stone cold start up and put it in Drive right away and pull out. It goes away after a minute, so I think it has something to do with the Air Injection system. The pump is mounted very close to the firewall. And what's on the other side of the firewall? A dash!

I guess a quick verification would be to just unplug the d**n AIR pump for a few days and see if the noise is gone. It happens too infrequent and when it does it doesn't bother me, so I never tried this.

Rob

03Bluerado · February 27, 2004

My 2002 has the same exact noise in the dash. sounds like it is coming from behind the insturment panel. I'm planning on trying to find it when the weather warms up.

COZ

Yeah, really sounds like it is coming from just behind the dash. Does not sound like an exhaust vibration as it really, really sounds like it is coming from the dash area.

But, will try to look around this weekend under the truck for loose exhaust pieces and will check the vortec cover.

The good (?) thing about this buzz is that there is no way in he11 that the dealer will be able to "could not duplicate" me. I mean this thing is LOUD and one drive around the lot will verify this!

YES YES YES YES!!!! I have this on my 03 and I was going to make a post about it but have just decided to ignore it!! I have a 4.8 and a 5 speed and can here it when I lightly rev the engine in neutral!! It sounds like it comes from the Tach, put your face right up near the dash and there is no mistaking it, it must be the cluster, I have only noticed these last couple months and have just over 20K on the truck. It sounds like a mechanical noise and like the others said, right when you tap the gas and the tach goes up to around 8-100 rpm and it makes the sound as the needle is returing to idle speed...its crazy!!! Maybe some one can have a dealer check it out...I know this is the cluster, no vortec cover, I have had mine on and off and its tight....it works fine, but man it doesnt sound good!!!

melbertbloosfan · March 9, 2004

Okay, thought I would bump this with an update.

Had the truck to the dealer yesterday for some stuff. Tweeter fell outa pass door (you'all might want to check yours - there is a TSB on it for NBS trucks), steering clunk (shaft lubed) and the darn buzz.

Wellll, it's gone! They relocated/insulated the trans dipstick tube! If you'all check the tube, you will note it runs right up against the firewall. Mine was vibrating when I took off from a stop. Today, no vibration/buzz. I'm a happier man.

Sooo, gents, check the tube and maybe make an insulator of some kind to move the dipstick away from the firewall and exhaust.

Good luck!!!

BTW, Dennis Hanks Chevy in Ozark rocks!

JBZ71 · March 9, 2004

Gonna check that tube out today,truck's going to the dealer next week,but if I can get that buzz to stop today I will be happy...Thanks for the update...

Mule · March 10, 2004

That makes a lot of sense really. When my truck had the headers put on, I am sure they moved it or knocked it and the buzz went away. Just worked its way back after 4 years.

I am going to check mine tonight.

jsmith555 · March 11, 2004

oh, hell yes... tranny dip stick. I just went out and checked mine and it's very close to those metal shields mounted on the engine firewall. Im going out there right now see if I can relocate/insulate and will post later. Thanks Melbertbloosfan!

jsmith555 · March 11, 2004

I really checked out my tranny dipstick, but its not even close to the fire wall. I did pad it temporarily, but unfortunatley this buzz is still there. Im bringing her back in to the dealership, a different one, for the third time.

Dissapointed!