jrk

Wrench, Would you please explain what a TSB is as you noted above. Thank you. Jrk

I purchased a 2015 GMC SLE in June 2015. The vehicle has a 5.3 V8 Ecotec3 engine which I think is causing the noise problems. If you select from the steering wheel cursor, the Fuel Economy window, it shows the V8 mode in the lower right hand corner of the screen. If you are stopped, it will show the V8 mode. As you accelerate and eventually level off your speed, the V4 will initiate (you can see it on the screen) and the noise begins. It's a deep droning noise. If you accelerate, it will move back to the V8 mode and it's quiet. The droning noise is more prevalent at speeds of 45 mph or greater. I took my vehicle to the dealer. They said that they drove another like car and it did the same thing (same noise). One of the service managers told me that it was the exhaust. I told him that I had driven a new Silverado pickup with the same engine and it didn't make that noise. He said that's because the tail pipe is 2 feet longer. The service manager in charge told me later that they can't confirm that is the problem. They said that they could dismantle the roof and check the insulation. I said forget it. That's not the problem. You can't tell me that this has been going on since 2014 and they don't know what the issue is. I think that it's definitely the engine causing the problem...not necessarily where the noise is coming from. I have contacted my dealership about this issue again today.