vibration/buzz at 1000 rpm

[Shaggnasty]

I've got a vibration/buzz at 1000 rpm that is driving me nuts. It's worse in cold weather and worse yet when the transmission is in drive. It seems to be coming from the front of the truck, maybe the lower drivers side firewall area. I've got an '01 Sierra ext. cab with the 5.3. Anyone got any ideas?

[COZWV]

I've got the same one! it sounds like it's inside the dash behind the instrument panel. DRIVES ME CRAZY TOO!

 

I plan on doing a more extensive search when weather is better.

 

COZ

[Markeaux]

I could swear I read a post on this same thing a few months ago ... sorry don't remember anything more, except I think they did find the problem.

[am70043]

I have the same problem at around 850 to 900 rpm's. You guys have described this issue exactly as I hear and feel it. When I get some time the truck will go in for warranty work and hope to reply back with fix.

[Shaggnasty]

bumping this hoping someone can help....

[Shaggnasty]

anyone? anyone? Bueller?

[jhm]

I had the buzzing noise starting 18 months ago. I bought it in and they couldn't fix it so they said it was piston slap! I got the 6yr 100k warranty out of it. About a month ago it got to the point where the noise was driving me nuts. I bought it in again, didn't mention the earlier wrong diagnosis, just said "you got to fix this!" They spent 2 days searching and finally discovered it was coming from the transfer case shifter. The shifter uses a plastic guide that rides on a plastic track. At certain rpm's, it would start vibrating and the noise would travel up the firewall making it sound like it was coming from the engine! They replaced the mechanism and the noise is gone! It is like having a new truck! One way you might be able to rule this in or out is to apply pressure with your hand to the 4wd shifter when it makes the noise, if it is like mine, the noise will stop.

[Shaggnasty]

I had the buzzing noise starting 18 months ago. I bought it in and they couldn't fix it so they said it was piston slap! I got the 6yr 100k warranty out of it. About a month ago it got to the point where the noise was driving me nuts. I bought it in again, didn't mention the earlier wrong diagnosis, just said "you got to fix this!" They spent 2 days searching and finally discovered it was coming from the transfer case shifter. The shifter uses a plastic guide that rides on a plastic track. At certain rpm's, it would start vibrating and the noise would travel up the firewall making it sound like it was coming from the engine! They replaced the mechanism and the noise is gone! It is like having a new truck! One way you might be able to rule this in or out is to apply pressure with your hand to the 4wd shifter when it makes the noise, if it is like mine, the noise will stop.

I got excited when I saw there was a response, but, tragically,

I have a 2WD truck. d**n. Anyone else???

[jhm]

I thought maybe you could have a 2wd, but the problem sounded exactly like mine except mine would only make noise while driving which made it real tuff to find. If your truck makes the noise in park, maybe you can have someone rev it up while you search. Chasing stuff like this is time consuming, but if you start feeling around you may just find the source of vibration. Good luck!

[foghorn23]

I've been having what sounded like similar vibration issues since the weather has gotten cold. It seemed to be coming from the dash area (maybe under the hood or firewall. I did a little investigating and here's what I found. The plastic cover on top of the motor with the Vortec logo is held on by one screw.

 

Vortec cover

 

Somehow, I guess engine vibration, this had become loose and was allowing the plastic cover to contact some of the hoses along the driver side of the cover

 

Side of cover

 

I tightened the screw and moved the hoses away from the cover. No more vibration.

 

Again I was seeing this at about 1000 RPM with the truck in reverse or drive. It wouldn't vibrate while in park. I hope this could be the answer for some of you guys. No engine problem, no tranny problem. Just a loose screw.

 

Good luck

 

Vroten

[Mule]

The ealier thread on the noise pointed to exhaust. Either a loose bolt or the heat shield on the muffler.

[ctoliver]

its probley the vortec cover, remove the cover it has two supports midway just dab a little silly cone on the feet and reinstall mine did the same thing and that fixed it!

ct

[k1500chevy97]

check to see if your heat shields are a lil loose . i had a vibration/buzz like what u are talking about on the 03 and a heat shield was loose dealer tightened it up no problem

[bansell]

Did the cover fix any other's problems..

[Shaggnasty]

I have the same exact problem!!! Did the cover fix any other's problems.. I am going to try that in the morning. Its so bad I would be surprised if it was the cover but I will try anyway!

fixing the cover helped, but did not fix the problem. I'm thinking transmission.