grinding noise at 42 mph

its under warinty take it back and tell them to call you when fixed.

If they won't satisfy you, switch dealerships. Sometimes it's possible that they are not even hearing the problem, or aren't sure how to fix it -- a lot of times with noises, a fix will come out later as possible issues are identified across the line. I'd have another dealership check it out. Ride with the tech, service advisor, or shop foreman until you can point out the noise to them.

Well, after 2 trips to the shop I have my truck back, grinding noise and all! GM put a bulletin out saying that the noise my truck has is "normal exhaust noise". Now Im stuck with it. I have driven 6 of the same trucks. Mine is the only one i can find with the noise. Its running me nuts! I wouldnt advise anyone to buy one of these trucks!

i tell you what that is the bigest bunch of crap i have ever heard of.if were mine i would take to dealer leave it ask for a dailey driver and tell them to call me when fixed,your truck will not sit long,they dont want the responability of your truck on their hands,i gurantee it will be fixed.

There is a bulletin out for the exhaust feedback through the transmission mount. They cut and install a flex pipe into the exhaust pipe before the cat. Just took my 2007 silverado in and had it done, noise is gone. Hope this helps :)

Do you know what the bulletin # is? I have the same problem with my 2007 PU. Dealer can't figure it out. What dealer did you go to? Maybe mine can call them?

there is a bulletin about an exhaust moan/vibration between 25-40 mph light load and it says to install Exhaust System Flex Pipe Kit and Exhaust Dampeners if needed, now i'm not saying thats it but just trying to help i'm a technician at a chevrolet dealership

I am new to this I have a 2005 silverado had a humming noise changed the u-jount and the humming is gone hope this helps

Is it fixed? Mine has same noise 40-42 light accelation and 50-52....

We just took our Silverado to the dealership for what sounds to be the same problem. They at first thought it was the U-joint. Had it for about 3 hrs, checked out the U-joint, said nothing wrong, everything is perfect...cost $156.00 for labour (which they said they only charged us for half the labour). As it turns out, the noise is gone.(at least for now). They said it has to do with the multi-flex fuel system and not to worry. We will be keeping a close eye on it though. Main thing is to get it check out so that it is documented in case of more problems in future. Good luck!

Just want to add, we are pretty sure it was the u-joint causing that grinding, vibrating noise because it is gone since they checked out the u-joint. Pretty sure they cleaned up around it...probably didn't want to put it through warranty so said it was fine and charged us for labour. Spoke to GM..even they felt the dealership probably cleaned up around it. They of course felt we were treated very fairly...which I do not agree. Anyway, just thought I would let you know...maybe concentrate on the u-joint and don't take their advice when they say this sound is normal...it is not. Good luck again.

boy, sure would like a direction on this; rattling kind of noise, sounds feel like coming from exhaust, BUT; replaced muffler, CATS are only 1 year old, occurs between 39-49 mph; not RPM related, does not seem to affect performance; frustrating, cant seem to lose this noise; HELP??

I have a 2009 Silverado and was having the same rattling noise at about the same speeds. Had a guy suggest running higher octane fuel to try and clean the system. Worked like a charm I ran 2 full tanks of premium and then gradually dropped back to mid grade, still haven't had a problem but I haven't tried going back to the lower grade fuel.

Just catching up on a decades worth of frustration 2004 suburban. Going crazy over the noise. It seems to happen at 1300 to 1400 rpm, under 35 mph. Doesn’t happen when I have passengers in the car. I wondered if because of the rust it wasn’t a body mount issue. I’m going to try high-octane first and then the U-joint. After that I might just drive it off a cliff.

Take it to a dealership all you want. There is no fix for the issue. I work at a GM Dealership. I had a 1978 Camaro that made the exact same noise. My current vehicle, a 2021 Silverado 1500 does the exact same thing.