Infernal rear knocking!

[Breandawg]

I've checked all the usual culprits. Parcel shelf, rear seat squabs, spare wheel well, I've folded the rear seats down - no difference.

Rear right side, usual low speed of rough roads. Sounds like a knock, kinda hollow. I've removed the wheel arch liner and the shock seems fine, including the sleeve thing around it. Rear springs are good and I've replaced the isolators.

Any known culprits? Car drives right, suspension feels good.

 

[atlantaM3]

check the bushing where the suspension beam mounts to the body. Those have a fair amount of give in them to begin with, so if worn out, could be a noise point.

 

[SteveS]

exhaust hitting something?

 

[Breandawg]

Axle bushings is a possible culprit, though they look fine. Worth investigating further. I'd consider replacing with polyurethane but I've heard that reduces the cars propensity for liftoff oversteer, which would be a great shame!

The exhaust was swinging about but I've replaced the old hangers with polyurethane and it's good now.

A rear numberplate late was rattling in it's housing, I fixed that too, sadly it didn't cure the knocking.

 

[Downsy]

How many miles/kms? I generally consider suspension bushings on a street driven car done for around 100-150k miles depending on how you drive it. Also pull out the cargo floor and spare tire and make sure something didn't wind up down there rolling around.

 

[Breandawg]

How many miles/kms? I generally consider suspension bushings on a street driven car done for around 100-150k miles depending on how you drive it. Also pull out the cargo floor and spare tire and make sure something didn't wind up down there rolling around.

70k miles. I've checked under the spare wheel well good. If not the bushing itself could it be the shock itself? I suspect not by who knows.
The car does get thrown around roundabouts quite a bit not excessive fast or aggressively, but it probably takes a toll on the bushes.

 

[LilPartyBox]

My rear has knocked every winter since new through the OEM suspension and 2 aftermarket setups. Once spring rolls around up it goes away every time

 

[Breandawg]

My rear has knocked every winter since new through the OEM suspension and 2 aftermarket setups. Once spring rolls around up it goes away every time

That's nuts! It's pretty cold here at present and it has seemingly exacerbated the issue.