Odd Noise Avalanche and Tahoe.....

[David Smith]

I am posting this in the Avalanche section, but I had the exact same issue in my 01 Tahoe.

So my current '11 Avalanche seems to have this weird tapping/knocking sound. It is very hard to describe. It seems like it is coming from the passenger side near the B or C pillar. The best way that I can describe what I am hearing is as if there was a bolt in a hole and the bolt was too small so it was just kind of rocking/shaking around in said hole. It does not do it all the time. On the way in to work this morning, I would only hear it between 45 and 50 mph. Does not do it all the time. Does not seem the change with road conditions (it will make the noise with or without bumps in the road).

I have been under the truck looking for just anything loose and I turned up empty handed. The noise is not very loud, but I can hear it barely over my radio at normal listening volumes.

Please tell me someone on here is having this same issue. I figured that since my last 2 vehicles have done the same thing, maybe someone else has experienced it and found where the sound is coming from.


HELP!!!

 

[David Smith]

Come on! Surely someone has this same issue lol

 

[63Blackseries]

If you have a video of the sound that might help a bunch.

 

[David Smith]

If you have a video of the sound that might help a bunch.

I don't. I can try and get one, but the sound probably is not loud enough to hear it on a video.

 

[David Smith]

I tried getting a video, but the road noise drowns out the sound and you can't hear it...Sounds like I may just have to deal with it

 

[Doubeleive]

I tried getting a video, but the road noise drowns out the sound and you can't hear it...Sounds like I may just have to deal with it

Habe you checked the exhaust system? A broken hanger can make a noise and sometimes the muffler, get under it give it a good bang and shake from different angles

 

[David Smith]

Habe you checked the exhaust system? A broken hanger can make a noise and sometimes the muffler, get under it give it a good bang and shake from different angles

I did not see anything obvious from underneath. I will get under it again and try hitting and shaking a few things. It just seems odd that it did the exact same thing in my Tahoe before I sold it. Thought it might be a common thing

 

[Doubeleive]

I did not see anything obvious from underneath. I will get under it again and try hitting and shaking a few things. It just seems odd that it did the exact same thing in my Tahoe before I sold it. Thought it might be a common thing

I have had mine do it before, figured it's worth a try, could also be a catalytic converter (maybe)

 

[David Smith]

I have had mine do it before, figured it's worth a try, could also be a catalytic converter (maybe)

What did yours end up being?

 

[Doubeleive]

What did yours end up being?

I've had it be either one and one time it was a loose bumper mounting bolts, that one took a long time to figure out, found it by accident when I bumped into the bumper and it wiggled.

 

[swathdiver]

Next time the truck is idling, listen to that right cat up close, maybe give it a tap or two with a hammer. Same with the third one (if you have it) in front of the muffler.

 

[David Smith]

Next time the truck is idling, listen to that right cat up close, maybe give it a tap or two with a hammer. Same with the third one (if you have it) in front of the muffler.

I have never heard it at idle, but I will get under it and check for loose bolts/hangers and bang around on a few things.

 

[swathdiver]

I have never heard it at idle, but I will get under it and check for loose bolts/hangers and bang around on a few things.

I'm thinking a piece of honeycomb in the cat has broke loose. Might only move around when you're on the road though as you described but worth a shot.

 

[David Smith]

I'm thinking a piece of honeycomb in the cat has broke loose. Might only move around when you're on the road though as you described but worth a shot.

Would it be loud enough to hear in the cab though? It only makes noise right around 50 mph. It does it on smooth roads too...

 

[swathdiver]

Would it be loud enough to hear in the cab though? It only makes noise right around 50 mph. It does it on smooth roads too...

Maybe, if its just a walnut sized piece it can bounce around, get jammed in place and then bounce around again with no rhyme or reason. That's not all it could be though. Could be a bolt, exhaust hangar, a door fastener, etc.

 

[David Smith]

I got somewhat of a video...with the road noise it is very hard to hear. skip to about 20 seconds and turn your volume up with headphones in. Let me know what you think...if you can even hear it.

 

[swathdiver]

I heard it but not sure what it could be from that.

 

[David Smith]

I heard it but not sure what it could be from that.

It is so hard to hear, but in the truck you can hear it pretty well. It only happens from 45 to 55 mph. I am going to try and get under it soon and shake a few things around. It is supposed to rain for the next 5 days, so I will have to wait for a dry day.

 

[swathdiver]

One thought that crossed my mind when I heard that noise was u-joints. Have you pulled and inspected them yet? Those speeds are about when the truck gets into 5th and 6th gear and the driveshaft begins spinning faster than the motor.

 

[David Smith]

One thought that crossed my mind when I heard that noise was u-joints. Have you pulled and inspected them yet? Those speeds are about when the truck gets into 5th and 6th gear and the driveshaft begins spinning faster than the motor.

Not, but I will check them for abnormal wear or play when I get under it