bumps and noises under 2011 9C1

[casalu]

I recently purchased a 2011 9C1 from the police department and the car has 115,000 miles on it. Thanks to Bill and Maurice for their invaluable advice and time helping with suspension questions. I have successfully had the SS springs and brand new OEM struts, shocks and rubber mounts installed but still have bumps and noise at low and high speed. I have put the car up on the lift and can't find any worn out bushings that I can see. I'm willing to replace these but not interested in throwing money at the wrong place. Does anyone have any experience with this and suggestions?

Tracey Holtzclaw
tracey@dhpre.com
864-304-7581

[Raunchtastic]

My car started making a soft "clunk" on the drivers side front strut, and more recently, on the passenger side. If you find out what it is, be sure to let us know. I am thinking my suspension is all original, so Ill have to start looking to replace it all. I would check the strut mounts. I haven't looked too much into how the suspension is, but on my Camaro there is a bearing that goes bad over time.

[9C1fanatic]

Check the strut tower bushings. Not the ones you can see under the hood but the ones that go under the tower, on top of the strut. They wear out and will cause this. I have also seen this problem right after new struts have been installed if the installer does not pay close attention to how they reassemble the new strut-spring. I had one leaking strut get replaced at the dealer and the tech put one of the washers on the wrong side of the tower causing the upper part of the strut to clunk against the top of the strut tower. These bushing I talked about earlier are supposedly the same ones used in the 04-06 GTO and are not the best quality, but that's just what I heard on the G8 board, maybe ours are made of different material. There are poly ones available.

[elc32955]

Don't think this is anywhere near the cause but I'll post it regardless since it refers to "clunk" when a vehicle is moved forward. Found this on the GM Tech-link page...

Some 2012–2015 Camaro SS, Camaro ZL1; 2013–2016 ATS; 2014–2016 CTS (VIN A); 2014–2015 Camaro Z/28, Caprice PPV, Corvette, and SS models may be hard to move after the vehicle has been parked for a period of time. A crunch sound right before the vehicle starts to move may be heard. Depending on how long the vehicle has been parked, the weather conditions in which the vehicle was parked, and how recently the vehicle has been washed, the condition may be a simple noise when the vehicle first moves or, at the extreme, the vehicle cannot be moved out of the parking space.

This condition may be due to the brake pads freezing to the vehicle’s rotors. Do not replace any brake components for this condition. High performance brake components (Fig. 11) have a tendency to lightly bind, often noted as resistance, and then lightly clunk when attempting to move the vehicle forward or rearward after a cold soak. This is usually noticed after parking, when the brakes have been wet, such as when driving in the rain or just after a car wash. This is expected of high performance brakes with high friction pads and does not affect the operation or performance of the brakes.

If a residual roughness is felt when braking, it can be easily cleaned by applying the brakes several times until the roughness is gone. If washing the vehicle prior to long-term storage, it is recommended that the vehicle be driven and the brakes applied several times before storing the vehicle.

Eric