Help! 2007 C6 Z51 6 sp manual - metal-on-metal grinding noise and lifter problem

[BillMLB]

RE: 2007 C6 w/Z51 pkg and 6 sp manual transmission


I'm having two non-consistent problems and wondered if anyone else has had similar problems?

1) When I first start-up the car, sometimes I hear a tapping noise and think it might be the lifters.

2) After backing up, I shift into first and after a few hundred feet, I sometimes get a very loud metal-on-metal grinding noise. It kind of sounds like a very loud bicycle chain slipping and clanking against a metal shield. The noise lasts for a few seconds and doesn't always happen.

Naturally I cannot duplicate these problems when the car is at the dealers!

[dtammen]

I have an '05 C6 Z51 w/6 sp. with 24k miles. Recently noticed a fairly loud clunking noise at low/lugging rpms especially while backing out of my driveway. I've also heard it when up shifting in a casual/non-sport driving mode. Not sure I would describe the noise as grinding though. Kind of how a worn U-joint or sloppy rear end would sound? The noise seems to be lessened as the car warms up??

It was in the dealer today to check it out, and they produced a TM that referred to this phenom and summarized the noise as 'a normal torque reversal in the driveline' and is 'a normal characteristic and not a condition of operation concern. No repairs should be attempted.'

I wonder how many other 6 spd. C6'ers have experienced this phenom? I'm not exactly on-board with GM's evaluation and recommended actions on this matter, and would appreciate any supportive comments.

[NORTY]

Any modifications?

[dtammen]

Nada. Just a stock C6 with the Z51 perf. pkg.

I'm going to a major Corvette dealer in Joliet, IL for a second opinion. We'll see what they find and recommend. The way it is now, is totally unacceptable to me.

[motorman]

Originally Posted by BillMLB

RE: 2007 C6 w/Z51 pkg and 6 sp manual transmission


I'm having two non-consistent problems and wondered if anyone else has had similar problems?

1) When I first start-up the car, sometimes I hear a tapping noise and think it might be the lifters.

2) After backing up, I shift into first and after a few hundred feet, I sometimes get a very loud metal-on-metal grinding noise. It kind of sounds like a very loud bicycle chain slipping and clanking against a metal shield. The noise lasts for a few seconds and doesn't always happen.

Naturally I cannot duplicate these problems when the car is at the dealers!

check the axle nuts when cold.

[Norseman]

Read my post on Differential Pro. I have a feeling it is the same pro. Mine used to make the same noise on backing up and cranking the wheel to get out of my driveway. Now it's completely gone after the additive to my diff. lube.

[dtammen]

I posted some good news and hopefully good information on the clunking rear end issue in the 'Differential Problem' thread, originally started by Norseman.

Thanks to all who contributed suggestions.

[Fegs]

Same noise, same answer... 05 Z51 6sp