I have been dealing with an annoying knocking/clunking noise for the past several months, and I'm starting to run out of ideas.

There's this knock/clunking noise that appears at the front right wheel area (or at least it seems to be) whenever I drive on uneven/rough roads, which is pretty much everywhere here in the UK.

In the pursuit of fixing this issue, all four shocks were replaced with new ones (and because I was there, added some new lowered spring hehe). The shock mounts were also replaced and droplinks too. Very pleased with the new setup but got disappointed shortly after leaving the garage when the same knocking noise was still there....

The MOT was due a month later, so figured if something is wrong it will be picked up then. So last week was MOT time, and indeed the car failed on the rear lower wishbones. So both rear lower wishbones were replaced and shortly after leaving the garage, again that knocking sound which seems to come from the front right of the car was still there...

Now the car has passed its MOT with new rear lower wishbones, it kinda rules out a suspension issue, otherwise it would have been picked up during the inspection. I believe during the inspection engine and transmission mounts are also checked and no mention of these being defective. Brakes would have also been checked and nothing there too.

Any insight on where such knocking/clunking noise could come from, if it not suspension related?

 

Front upper wishbone(control arm) - common fail and the thunk comes from EITHER the ball joint or the bushes. Check torque on the bushes.

 

Does anything you do affect the issue ? like applying brakes, accelerating, turning. or does it only happen when the vehicle gets a good shaking from rough surfaces, as if an exhaust pipe hanger is loose letting a pipe hit.

 

I’ll check them, you never know, but I’m not convinced it would be that. If it is I’d be surprised as it hasn’t been picked up on the MOT which would have been an instant fail.


Nothing I do affects it. Driving home tonight I tried to pay more attention to it and it actually seems to happen when driving above holes rather than bumps. Rarely happens when going over speed bumps. But cracks and holes on the road that’s where it seems to happen the most. I’ll put the exhaust on my checklist.

Probably going to have a good look at it over the Christmas holidays when I’ll have some time to tinker.

 

yeah I don't have a grasp on what MOT is. Almost reads like they test drive the car. Here in the US and more specific in my State, we had an annual inspection but the then Governor killed the program calling it a waste of taxpayer $. but even then, they just connected sensors to the tail pipes to read emissions and ran a micro under the car to determine leakage or lack of CATS. At any rate, there is a stretch of lakefront road that has more holes in that Albert Hall and after replacing my front uppers, I didn't torque one of the bolts, thunk thunk thunk. I torqued it and it resolved.

 

One possibility not mentioned, probably because it does not seem related. But a knocking noise under these circumstances can be caused by the bolt at the engine bay brace bars not being fully tightened. There is an old thread on this. The noise is transmitted into the cabin.

 

i once fooled myself into thinking i had a front upper ball joint failure, but the clunk sound was so occasional that i did nothing about it.

weeks later i discovered it was the socket for my wheel locks, loose in the glovebox. i now wrap that up inside a soft winter hat.

 

Put the car on a two post lift and hit everything with a big soft-blow hammer.

 

oh also, i think without disc retainers, it may be possible for some brake discs to rotate a degree or two and clunk against the wheel studs. mine seemed to do this consistent with what i was doing: first launch of the drive from any stoplight if it was vigorous enough, get one clunk, then never again until the next day of driving. probably was "resetting" itself in the mornings while backing out of my driveway.



if you have aftermarket wheels/discs you might consider a couple extra pounds of torque over spec. i only go 3 ft-lbs over spec, i think 5 would be pushing it. i no longer hear this particular clunk even though i still don't have these.

until recently i didn't even know these retainers existed, they weren't on my car when i got it. in fact, story-time for the rest of this post: i ordered some from british parts (.co.uk) over a month ago, have an email confirmation with my information and an order # on it. they never fulfilled it nor emailed/phoned any cancellation notice, and when i finally emailed them the other day -- replied and quoted my order, too -- they pretty much blew me off like the united states doesn't even exist.



the option to ship to the US has since been removed from their online forms. not that terrible really, but i hope they treat other customers better than that.

 

If you're going for MoT, you may get an advisory on the front suspension due to the noise(s).

Did the garage that replaced the dampers check the roll bar bushes on the front crossmember?

 

I have same issue, been trying to find the source for some time now!
typically on uneven roads which shift the weight of the vehicle from side to side causes the knocking

 

My sway bar bushes have worn out and clunk loudly if one wheel hits a bump. If both hit equally, there is no clunk. Disconnect the drop links to see if you have vertical movement of the bar in the bushes.

 

bushes covered, shock mounts and isolators. did anyone mention engine mounts? Sorry, I missed that.
tie rod ends typically don’t knock. Sub frame??
And do not laugh… a tool left in the cowl?

 

I also had a very annoying knocking noise from the front of the car while driving on uneven surfaces. It started about a year ago and was a very slight noise. As time went on, it became louder to the point that I didn't want to drive it anymore, it was just so annoying.
I tried replacing the upper control arms, the shocks, and the end links all with no improvement. I was sure it sounded like Sway bar bushings but with the end links off i couldn't see any play. which is why I tried these other things first. Then i drove with my end links disconnected and awwwww, no noise. It took me several hours to remove and replace these sway bar bushings and even though they didn't look bad, with the new ones installed it feels and sounds perfect.

 

Spot on!

 

Thanks for your input! As time went on, and despite trying my best to find the source of the problem, it started to become second nature, and have yet to sort it out with other issues that needed looking at.

I’ve been thinking that it may be the anti roll bar bushing but couldn’t think of a way to test them. The car has even been through the hand of multiple mechanics and multiple MOTs by now (most recent being last November) and despite mentioning it, none of them could see any issue…

I’m currently on the lookout for a decent used front subframe due to heavy corrosion. I will be doing the anti roll bar bushes and engine mounts at the same time. I’m hoping that will resolve this knock for good before this year’s MOT.

 

FWIW, the bushes are fairly easy to test. Disconnect the stabilizer links and tie them off temporarily. Drive around (stay off the highway). If the noise went away, you found your problem.