Vibration in dash
 

Hi guys, I haven't been on a corvette forum since I got the 2007 with 5,000 miles about 5 years ago. I was on a lot with my C5's but this C6 has been perfect up until this year. It has 32,000 miles now. I started noticing what I thought was a noise like something was loose and at highway speeds it would flutter with the wind. Could not find anything. My service man said my front tires were cupping so we replaced them, did a full alignment and balance, still the same thing. After a while I believe a lot of the noise came from a poorly installed cabin filter. Now when driving 60 to 75 I may hear a vibration which seems to be in the dash but it is not all the time, and when my service man takes it for a drive it doesn't do it. My question is, since I think my tires, balance, and alignment are okay what else could cause this. I feel nothing in the steering, etc. What would a bad wheel barring sound like and how can you check it?
Sorry for the fragmented post, but the noise is driving me crazy and the bad part it is not all the time. I've tried to determine if it does it when could, hot, in automatic, or paddle shift, in different gears, none of that seems to matter, but it is definately speed related. The car drives and rides excellent other then this chatter.

Thanks for any suggestions
Jeff

Welcome to the forum.

Maybe put it up on a lift and check for any loose plastic parts for aerodynamic purposes.

edit: Missed the part about the dash vibrating. I take it you can't feel it in the steering wheel or seat at different speeds.

Yea, I've put it on a lift and checked under the car. I don't feel anything in the steering or seat. Now the last two days it hasn't done it and car rides great. Some days it makes noise and others it doesn't, it is not consistent at all.

Thanks for your help

My 13 Grand Sport does the same thing. Mine is the plastic piece in front of wind shield. open hood and tap on it might rattle.
Best of luck.
David