Hi All
A while back I posted that I had issues with my car ‘clunking’ when going over speed bumps and pot holes, even if going over pot holes at a very low speed (I first noticed noice after its MOT but could’ve been that I’d alwys had music on). I took my car to a garage twice (2 different garages) and both said they couldn’t see anything that would cause the noise and drop links were fine.

It’s been a few months since I’ve let the noise bother me but after my boyfriend crashed his car a fortnight ago and he’s been driving my car, I’ve been driving my sisters cars and am jealous at how quiet theirs are. One sister has a 2014 fiat 500 and it’s almost Silent over bumps.

I’ve now started to stress about the noise again and googling have noticed ‘bump stops’ being mentioned. Could this be the cause of the clunking? Are they an MOT failure and could have been missed on my mot? Finally, if so how can I tell if mine are in need of replacement and how do I replace?

Thanks in advance

There are lots of reasons cars clunk and knock over bumps and pot holes.

You don't say if it's from the front of the car or rear?

Common issues at the rear are the bushes in the top mounts to the rear shock absorbers.
These wear away and cause a double knock from the rear over bumps.

The trick to spotting them is to have someone bounce the back of the car vigorously, while you watch the top of the shock, where the bolt is, just to the top/behind of the rear wheel.
It should all move as one, up and down smoothly.
If the bolt head moves before the rest of the shock mount moves, the bush is fecked.

Bump stops up inside the rear springs can rattle about, they are only clipped in and can flap about a bit.
You should be able to reach in and give them a gentle twang, see how bad they rattle.

Loose items in the boot, spare wheel and tools, rear seat belts flapping around, rear seat backs not clipped upright properly or their clips and strikers are loose (so the seat back can be rattled even when clipped in properly) and exhaust or silencer knocking are other culprits from the rear.


Anti Roll bars and their drop links can rattle.

The D bushes that hold the bar to the car aren't too well known for wearing on these models, but can wear away so the bar rattles a little.
It's usually a muted, quick rattle over broke road surfaces as the bar is only moving a few millimeters either way.

Drop links can cause a right racket but are hard to spot as they are under tension most of the time, particularly if the car is jacked up and the weight of the wheels pull them down.

They tend to rattle just as the weight comes on and off the wheel over the bumps and rough roads.
They can feel like something is badly loose under your feet (or passengers feet).
They are prime suspects for rattles at the front and as they are fairly cheap and easy to replace, most owners will change them as matter of course if they are suspected.

Worn suspension wishbone bushes can cause the wishbone to clonk about, you really need a bar in to jemmy the bush to see how far it moves.

The top mounts on the front suspension can wear and cause slop in the top of the struts, these can rattle.

Steering racks can rattle in their cases.
Any lash in the pinion to rack joint will cause the lot to rattle about (my 2012 panda suffers this).
It's particularly common on the non hydraulic racks like these, there's no fluid in them under pressure to mask the lash (there's always a little lash) like on a conventional hydraulic power steering system.

You can take your pick of the above, but if you can narrow it down to where and how it's making the clonking, it should help with trying to pinpoint, test and eventually sort it out.

Though the MOT test to most of us is quite a vigorous test, it really can't test and spot every problem just sat up there on a ramp!
Think of them testing important items like brakes to a standard just above complete or imminent failure!

My wife's car made terrible noises going over speed humps, a "rubber squishy noise " I replaced ALL the front suspension parts, though I re-used the top mounts (mistake, were serviceable now not but not too much of an issue) once replaced TOTALLY silent, so if you want no noises, replace all the front suspension parts and the rear shocks, it's not as expensive as you might think for the parts if sourced carefully AND you(boyfriend? ) can do the work oneself?

Just changed front shocks on my Dualogic. Huge difference. No suspension noise at all going over bumps.
Trouble is, now the rattling dash and vibrating door mirror are much more annoying than they were... guess I'd better fix them next.

Thank you. Definitely going to have to look st all of these during the week and get it sorted.

Drove it tonight for the first time in a fortnight and the noise sounds to me maybe more from the middle/rear of the car.

Also tonight the number plate warning light came on and BOTH bulbs were out... this happened last year with one bulb, thecwarning woild come on, go off for a few weeks, come on... eventually changed bulb and has no issues for a year until 2 weeks ago the warning came on again and one bulb was out. Stopped until last night when one went out again and then tonight they both went out. Switched car off, went inside for a bit, came back out and both were working again. Been to Halfords and replaced bulbs so hopefully they’re now fine but convinced it could be dreaded hatch wiring (although I never open my boot).