I have been hearing a knock in my rear end the past two days. I installed bc racing coilovers and they work great. Everything is bolted tight. There are no unusual vibrations. When I'm driving usually below 20 mph there is a knock in the rear end and it sounds like a sway bar popping. Sometimes it happens over bumps and sometimes on flat road. It is not a continuous noise, it is sporadic. It sounds like a sway bar that isn't tightened correctly. Is it possible I need to go back and retighten my sway bar? Despite the fact that I did not touch it when I installed the coilovers.

 

When you torqued all the suspension bolts, did you compress the suspension or did you just leave the whole car resting on jackstands?

 

I had a similar issue with my BC n+ on my old car, i had it replaced under waranty and everything was fine afterwards.

 

Go through and check all torques, bushings, and end links/sway bar. Negcamber already touched on it but it is important to preload the suspension before you torque all the bolts.

Or possibly it could be as simple as something in your trunk bouncing around.