Hello,

A few months ago, I had ST coilovers (part #90321) installed on my 2012 Fusion at a local shop. The install went well at first and the car handled great. However, after a few weeks the car developed a loud clunk/popping noise in the rear left. I took it back to the original shop and they thought it was likely a bad endlink. So I ended up replacing the endlink to no avail, the noise was still there after. Next, I took the car to another local shop and they had an idea that it was the spring isolator. I emailed ST and they said there should be no isolator installed, just the spring perch included in the original kit. So I sent them a picture of both sides and they said both sides looked ok. They thought that one side was probably a little higher than the other and sure enough they were right - the left side was about half an inch off so I raised it. Still no luck, the car is a little less harsh now but the annoying clunk is still there.

I'm wondering if it's possibly a bushing - such as one in the Upper Control Arm making this noise and the shops are missing it. It's been driving me crazy and I'm not sure what the next option is short of reverting to stock.

Thanks for reading! Any help or ideas would be greatly appreciated.

I'd be inclined to reinstate the original suspension, which presumably didn't clunk.