Suspension knock, not your average clunk!

smy0003 · Postby **smy0003** » Fri Oct 24, 2014 4:46 pm

Hi guys. My mx5 has been making a strange knock for a while. Generally going over undulations at slow speed or when the car pitched. I changed out the shocks and springs a few weeks ago and it was still there. Hmmmmm....

It sounded like something hollow hitting the underside of the car, so I suspected the exhaust. It happens when i enter and exit my car as well as on the road. Although strangely sitting in the passenger seat didn't produce the noise.

Fast forward to today and I have found the issue. The metal under/around the rear left drivers seat bolt is flexing, and the sound of it popping back is the mysterious hollow knock. I used my foot to isolate the location, you can see and hear in this video below.

Any ideas as to how to solve this?
Big washer?
Metal plates to spread the load?

Is this a common thing?

The underside of my car is in excellent condition, and have had multiple mechanics compliment how straight and clean it is.

I'm glad that I don't have to spend the dosh on new bushes, but I'm stuck.

Any help appreciated as always.