Went to the dealership for the chattering, worbling, noise, what ever its called. Took mechanic for a ride, asked me to take others for a ride. Took out two,base models and two grand sports. Two base models were the same, can't believe it. Two grand sports I could hear the noise but it harder because of the ground effects package. I was told that's the way they are? As soon as I start up an incline around 1500 rpm the chattering starts. Lots more about this on the American site. I guess next is the service manager then GM. So that's the way they are, we are just suppose to accept the bad parts. I guess
Hey Vetting:
Sorry to hear of your problem.
It's important to differentiate between the infamous "warble", which is caused by insufficient fluid in the differential, the well known "shudder", which is the failure of the lock-up clutch in the TC and plain old road noise for which the C7 is famous. Those big Michelins, combined with varying road surfaces, can put out some pretty significant vibrations and oscillations which lead to a fair bit of cabin noise. The fact that you drove 4 new C7's and found them to be the same, or similar, tells me that it may well be road noise. It's also possible that you're hearing something else entirely like a torque tube problem or a tire issue, but it's not likely.
I don't now how close you are to your next oil change but at that time, or sooner if you're really concerned, get the dealer to check the fluid level in the differential. I just changed mine, 2019 GS with 4000 kl, and it was about a half a quart low. The dif takes approximately 2.8 US quarts. This was not enough to cause the warble noise. The warble problem was primarily related to a limited number of 2015 and 2016 C7's where the dif was under-filled by about 1 quart as well as having incorrect shimming on the pinion. It has not been a major problem with later models. The videos in this post, #3, may be helpful:
Warble noise 2019 C7 - CorvetteForum - Chevrolet Corvette Forum Discussion.
To check for TC shudder, take the car out on a long, flat stretch of road. Make sure that you're in "D", take it up to 100 - 120 kl and hold a steady speed. It doesn't matter what drive mode you're in, Tour or Sport will be fine. Watch your display and look for the change from "V8" to "V4". If you see an RPM variation of 100 to 150 while in "V4" mode and you can feel the shudder, like driving over a rumble strip, then you may have the TC problem. It would be helpful to know the mileage on your car but, being a 2019, it's unlikely that you have enough on it to be experiencing the "shudder".
Try these few things, they might help you narrow down the problem. Based on the information provided, my guess is that you're just experiencing the normal sounds of this exceptional car.
Best regards
Ross