Hello,

I bought a 99 C5 coupe with 105,000 kms on it. Upgraded brakes, exhaust and rims. One owner previously who is an elderly gentleman and he took great care of this vehicle. Uses the same dealership I do for service as well. His wife passed away recently and she told him to trade in the C5 and buy the new C7 and that's the only reason why he sold the vehicle (what a woman! God bless her soul!)

I only have a 30 day warranty on the vehicle. There were a few small items but I have two major problems:

1) Pulsation. Unfortunately they replaced the performance brakes (rotors are drilled and slotted) for the OEM brakes which seems to have solved the pulsing issue a little. They did fronts and will do rears soon. I have requested they return the performance parts back to me. My question: could I take the performance brakes somewhere to have them retrofitted? The service department said it was not likely but I think they didn't want to pay the cost of doing so - buying OEM parts was a cheaper solution for them maybe? Or maybe they can't be retrofitted? I'm not a brake specialist and I know little of performance brakes for corvettes. The OEMs look ok but the performance brakes looked RAD.

2) Vibration. This underbody vibration can be felt ever so slightly at around 110 kms/hr. It "feels" like it's vibrating at a 2 seconds on and 2 second off pattern. Driving under 110 and it disappears. Service has "felt" and acknowledged that this issue exists however, they don't know what's causing it. They checked tires: tread, pressure, balance, alignment, etc. Maybe it's the drivetrain? Has anyone ever experienced this before? Does anyone have a guess as to what this could be? Service has not worked on this yet but the dealer has already hinted to me that they will buy it back from me and sell it wholesale to get rid of the car if the vibration becomes a costly fix. They said that to me 1 week into owning this vehicle and I was pretty upset at them. I have already bonded with my little read corvette.

Any help, general thoughts, comments or opinions would be greatly appreciated.

Thanks, Sarah

 

I have a '99 coupe that has the same cyclic vibration as you described. 60,000 miles on the car. I have replaced the tires and had the rims checked. Like you had the tires balanced, alignment was not the answer. Not a bad vibration just a little annoying on long trips. I feel it through my butt, not through the steering wheel. It only occurs in a specific road speed not around town.
No help here just similar condition.

 

No help either but eager to hear comments on this type of vibration. I have a on/off vibration as well. While running down the highway, if I go into a right-hand turn, and as I follow through the turn it goes away. When I go into a left-hand turn, and as I follow through the turn, it stays constant, it doesn't come and go. So, I figured it was a wheel bearing... Checked the wheel bearing on all 4 by jacking the car up, yanking at 12 o'clock, and 6:00 o'clock, opposite of each other, same at 9 and 3, found no play at all. I also took a prybar, placed under the wheel, one end on the concrete, other end my hand of course, and tire resting on center of prybar. Lifting up and back down, no play found either. My guess is, bearings OK, unless there is a better way to check the bearings. I'm guessing it is something more serious but anxious where to start looking next. Thanks in advance!

 

Mine seems to be a harmonic type vibration, just enough to notice, ie. can still focus my eyes! It does change in turns but both directions. I am not convinced it is a wheel bearing. More like a drive line, torque tube, something in that direction. As long as it stays this minor I will live with it rather than an expensive chase.

 

I get something similar on my '98 with 105K on it. I have noticed that the road surface does seem to play some part. Not sure if it's car related or just road surface, as these cars do let you 'feel' the road. Interested to hear other responses. Zuti

 

#1 just sounds like the classic case of warped and/or improperly bedded rotors. You could try resurfacing them, but unless you plan on tracking this car I don't see the point. The stock brakes are quite good and 110% adequate for street usage.

The #2 you describe is very common. (not saying it's a good thing just that there are many similar stories) I have the same cyclic vibration once I get above 60 ish MPH. I suspect that it's slop which has developed in the steering joints because it seems to only happen when I'm tracking straight ahead. Once I introduce any steering load at all it goes away (mostly).

I've also heard that it can be a sign of worn torque tube bearings. To date, I've never seen a post of, "This is exactly how I fixed it", regarding this issue.

 

Thank you everyone for sharing. I'll let you know how this all pans out as the pulsation issue is being addressed (rears have been changed - just doesn't look as nice as the performance brakes but as you commented - the OEMs are 100% adequate). Vibration is next so I'll give you all an update soon. Thanks, Sarah