Deville6978

I have a 2014 C7 Automatic standard package. I have over 100000 miles and have a vibration I want to diagnose. When I'm over 20 mph I hear a metallic sound as I am slightly applying gas. The sound is similar to the sound heat plates around the exhaust makes on most other cars when loose, but a consistent pattern This happens all the time when the car starts to go up a slight incline or when keeping cruising speed. Sound goes away when speed is slightly increased. The car will have a more profound vibration under the same conditions but the speed is above 65mph. My guess is the driveshaft, but would like to rule it out before I invest $1200.

23/C8Z

don't spend a penny until it is properly diagnosed and with the understanding in writing that the repairing facility is changing THE PART/S that are creating THAT issue.. otherwise you could throw parts at the car all day long...

My guess is broken cat media or torque tube/bearing issue. what does it do if you power brake the car at zero mph in forward and reverse?

Wesens

I am having a similar issue. I hear a metallic vibration at 1500 RPMs under slight acceleration. This car, 2015 Z51 A8 has a history of noise issues going back over 1 year. They replaced the fuel pump, flex plate, etc. That alleviated the issue for a couple of weeks, then the car began making another metallic sounding vibration. This time they torqued the bolts on the flexplate assembly (or somewhere around the flexplate) to 110 LBS. I'm not a mechanic and don't know much about it. That also eliminated the issue. But recently I am getting the same issue that you described here. Not only do I hear the metallic vibration (sounds like it's directly under the dashboard area, but sometimes it shudders under acceleration at the 1500 to 1800 RPM levels. That particular problem has me believing some bearings could be bad. I really don't know, but sure am tired of dealing with it. Good luck to you and getting yours resolved!

kenrobb

This may be out in left field, but the 14's had a problem with the belt tensioner leaking it's hydrulic oil and causing a noise when car went from 4 to 8 cyl and then back to 4 cyl operation. I thoguht it was somethng loose in the dash for sure.

Strake

Have you checked out this thread "Warble Sound Occasionally" ? So is your's a NOISE, or an actual VIBRATION?

https://www.corvetteforum.com/forums...asionally.html

It is a harmonic resonance vibration noise caused by a faulty ring and pinion in the differential.

I have a YouTube video clip posted in there several times that depicts the sound.

It's always at about 1500 rpm, light foot on the gas. Any gear, any driving mode, any exhaust setting.

Wesens

Mine is a repeatable rattle/noise at 1500 RPMs. It occasionally makes a vibration at 1500 RPMs under moderate acceleration

Deville6978

It was the belt tensioner. Chattering has stopped and no more vibration. Thanks!!

Wesens

Not out in left field at all. I finally got mine back after another week in the shop. I had to take the service manager on a ride to reproduce the sound which wasn't hard to do, but they apparently were unable to do. Final diagnosis, belt tensioner leaking. They replaced it and now it is quiet. I wish the dealers had as knowledgeable people working on Corvettes as this forum. You were spot on. Thanks!

direct007

Having a similar issue on my 2016 Z51 vert. Did the issue sound like a Rattlesnake or if you loaded a hollow tube with small beads and tilted it back and forth? I hear this sound at 1500 rpm in V4 mode only. Disappears at higher RPM and in V8 mode.

Trying to help my dealer diagnose the source of the noise.

Thanks!

Wesens

Yes, similar to your description. The dealer couldn't reproduce the sound so I had to take the service manager out for a drive. i was able to reproduce the sound at will. at 1500 RPMs apply slight pressure to the throttle and the sound will come back. I still feel a very subtle vibration going through 1500 RPMs and I believe that is due to the flex plate issue they supposedly fixed. Are you able to reproduce the sound at will? I would definitely have them check the belt tensioner first. Good luck. Those little noises and vibrations can be frustrating and annoying.

direct007

Thanks, I will advise dealer to check this. As soon as the car is at 1500 rpm and in V4 mode...the rattlesnake sound appears. Never happens in V8 mode or at other RPM's.

owc6

You have over a hundred thousand miles? Good on you!

Cant really help on the problem, but wanted to say it's nice to meet a fellow driver.