Knocking at rear
 

Over some bumps, I'm getting a rattly knock at the rear of the car. It's like a heavy plastic sound, or could be metal - I'm not sure. I thought it was the engine compartment not locked tight enough but that seems okay.

A garage gave it a quick check for me and said there's no play in the suspension of any sort. I've just replaced the discs and pads so it's not calipers, and it's just passed its MOT so it's nothing serious.

It's just really annoying!

It does sound like something rattling as if it's not tight enough. It's not a heat shield rattle, it's more thud-like than that. It almost sounds like a drop link starting to go, but the drop links are fine.

What could I check for, and how would I check it?

Thanks :)

I'm guessing it's more so with the roof off....?

I get it too, car just sailed thru her MOT and nothing worn or damaged underneath..?

I couldn't really tell you if it's more with the roof down, as far as I was aware it sounded the same but I'll double check. But yeah, nothing worn underneath and no play in anything.

Gonna guess it's your rear trailing arm(s):

http://986forum.com/forums/performance-technical-chat/53590-rear-suspension-noise-over-tar-strips-6.html

You won't find any play while on the car, but replacing fixed the loud clunks over lumps and bumps for me at least.

Thanks for that, I'll definitely look into it. It's a shame it's something I can't test before finding if it's faulty. I don't want to go randomly buying parts but it looks like I may have to.