Clunking from rear of car when going over "imperfections"

Clunking from rear of car when going over "imperfections"

Author
Discussion

MitchT

Original Poster:

16,695 posts

223 months

Tuesday 23rd May 2023
quotequote all
The OH's car (early 2005 E87 BMW 120d with about 100k miles in case it's of interest) is making a clunking sound somewhere at the rear when going over speed humps, bumps and general imperfections. I've been over it with a fine tooth comb to look for evidence of issues and not found anything. Coil springs appear fine, nothing is loose in the boot or under the boot floor where the battery resides, the folding rear seats are seated correctly, exhaust is securely attached, etc.

The car had its MOT recently and I've noted the following advisories from that...

Nearside Rear Upper Suspension arm pin or bush worn but not resulting in excessive movement inner (5.3.4 (a) (i))
Offside Rear Upper Suspension arm pin or bush worn but not resulting in excessive movement inner (5.3.4 (a) (i))

Could this be the cause of the noise and, if so, does it need attending to urgently or is it perfectly safe to continue using the car until it's convenient to get it sorted?

Hoofy

78,466 posts

296 months

Tuesday 23rd May 2023
quotequote all
Yeah - bushes sprung to mind. Especially if it only happens in the early stages when it's warmed up (ie the bushes have warmed up).

MitchT

Original Poster:

16,695 posts

223 months

Tuesday 23rd May 2023
quotequote all
Thanks!

Also, missed this...

Offside Rear Wheel bearing slightly noisy (5.1.3 (b) (i))

Scrump

23,380 posts

172 months

Wednesday 24th May 2023
quotequote all
Fixing the advisories from the MOT would be the obvious place to start.

alock

4,370 posts

225 months

Wednesday 24th May 2023
quotequote all
Always worth isolating other things. I've had two cars now where I was convinced the rear suspension was about to collapse from the knocking noises.

Both times it was the rear seat catches having a few millimetres of play. A bit of tape around the bar that the latch connects to, and the issue went away.

MitchT

Original Poster:

16,695 posts

223 months

Thursday 25th May 2023
quotequote all
Scrump said:
Fixing the advisories from the MOT would be the obvious place to start.
Definitely. It's the OH's car and, as usual, she'll "get round to it". I'm going to get them done instead.

alock said:
Always worth isolating other things. I've had two cars now where I was convinced the rear suspension was about to collapse from the knocking noises.

Both times it was the rear seat catches having a few millimetres of play. A bit of tape around the bar that the latch connects to, and the issue went away.
I wondered the same. The rear seats are really well secured - no play whatsoever - but I'll try a bit of tape anyway, see if it makes a difference.