Can anyone suggest how I can move forwards with this problem?

[hamster8]

A number of months ago, I had a clonking sound coming from somewhere under the front end of my 2006 A150. It seemed to start off on the driver's side, but now is much worse, and non-specific regarding sides. I am no mechanic and I have to rely on garages to fix things for me. Initially, I had the car checked underneath to make sure it was safe, and that it wasn't a damaged coil spring for example. I was forced to leave the noise to get bad, because often with noises, garage employees can sometimes be a bit deaf and struggle to hear it. At the first garage, they heard it alright, but couldn't figure out where it was coming from. They assured me that everything was all safe underneath with no visible problems. So, I had to have some other jobs done, so I took it to a different garage, where I have known from past experience, that they are good at fixing difficult problems. They did all the routine jobs but told me they couldn't find the source of the clonking noise. In desperation I decided that I would bite the bullet, and book the car into a Mercedes main dealer. I knew it would be expensive, but could never have foreseen that even they gave the car back to me unfixed. Where do I go now? I have to get this situation resolved. Very disappointed.

 

[KennyN]

Not much help but if the main dealer plus two other garages cant find anything wrong then there cant be anything serious as i am sure they have found something, if there was , to drum up some business.

If it has passed its MOT without the tester finding anything then i would just do your best to ignore it, as difficult as that would be , for me anyway.

If you are having to pay for all the investigative work rather than doing the work yourself then there comes a financial cut off point when it is not worth throwing ££ at a vehicle that is 16 years old and just live with the (safe) noise.

K

 

[Wolfie1]

So you have 2 options, keep replacing stuff till the noise is gone or leave it to progress to a stage where its detectable and just the part needed is replaced, although i am going to take a guess at a front shock broken inside it

 

[oldguy57]

If you are determined to get to the bottom of the problem, I would suggest taking the car to a good MB indie. Someone on here might be able to suggest one in your neck of the woods.

 

[geoffus]

The wife's car had a similar clonking sound, usually over bumps from the drivers side, turned out to be a broken front shock spring. But I know you have eliminated this common fault.

 

[Bellow]

A number of months ago, I had a clonking sound coming from somewhere under the front end of my 2006 A150.

What provokes it?
When does it occur - going over a bump, cornering, straightening up after cornering, during braking, etc, etc?
What is the nature of the sound - metallic, heavy or light sounding?
Is it a single clunk or several? If several, are they at the same frequency and intensity? Do the clunks suddenly stop or slowly diminish?

Identifying what provokes it/under what circumstance(s) it occurs can identify the components involved and narrow the search.

 

[sgregory124]

This is a real longshot but - you say the garages you've been to can't tell where the sound is coming from and that visually, all looks ok etc no broken springs etc.

I see your car has a manual gear box, on a previous car of mine, I had a very similar noise which only ever happened when I went over a bump or pothole with the clutch depressed. Admittedly mine turned out to be normal for the car (BMW M3), but it is something known as 'Driveline Shunt' and is to do with play in the transmission/driveline, which under certain circumstances can make a noise like that.

Mine was loud enough to hear inside the car, with the windows up and you could feel it through the seat, sounded awful - but was totally normal.

As I said, a long shot and a totally different car, but perhaps worth getting your chosen/trusted garage to check the clutch/transmission area?

 

[whitenemesis]

I had a clonk/groan type noise on my S203, slow speed turns and over speed humps etc.. Car was under warranty so MB tried to find the source. All the usual suspects checked out OK. After a number of visits they decided to attach chassis 'ears' a various points on the suspension and subframes. Techs took it out, one listening with headphones. The noise clearly audible but couldn't be pinpointed.
It finally took a very experienced and somewhat OCD (service manager's description!) tech to sus it out. It was the front crush boxes moving (as they should) against the chassis rails. The whole front end was disassembled and fresh grease applied to the mating faces. Two days latter all done and wonderfully silent.

Long story short, find a garage that can use chassis ears to try and pinpoint the source.

 

[MrGreedy]

As suggested, shocks are hard to identify, but could be culprit.

We could do with more info as suggested on how what why when this sound presents itself.

Options apart from shocks in my view that could be culprits in value order (lowest to highest)
drop links
Anti Roll bar bushes
ball joints
engine or gearbox mounts
any of the various suspension arms
subframe mounts

The first 3 items shouldn't be too expensive, but as you start to go down the replacement roulette route, there can be significant savings by just doing the lot in one go

 

[hamster8]

What provokes it?
When does it occur - going over a bump, cornering, straightening up after cornering, during braking, etc, etc?
What is the nature of the sound - metallic, heavy or light sounding?
Is it a single clunk or several? If several, are they at the same frequency and intensity? Do the clunks suddenly stop or slowly diminish?

Identifying what provokes it/under what circumstance(s) it occurs can identify the components involved and narrow the search.

The car makes no sounds at all if you are on a flat piece of road. (Hard to find nowadays!) As soon as you hit any bumps the noises start. The sound is pretty consistent. I would describe the noise as either clonking or clattering sound. Hard to describe noise in words - a bit like trying to describe pain to a doctor. Perhaps it might be helpful if I can record a sound file and upload it. I will see if I can achieve this!

 

[hamster8]

As suggested, shocks are hard to identify, but could be culprit.

We could do with more info as suggested on how what why when this sound presents itself.

Options apart from shocks in my view that could be culprits in value order (lowest to highest)
drop links
Anti Roll bar bushes
ball joints
engine or gearbox mounts
any of the various suspension arms
subframe mounts

The first 3 items shouldn't be too expensive, but as you start to go down the replacement roulette route, there can be significant savings by just doing the lot in one go

Thank you very much for your suggestions.

 

[Muckypaps]

It’s called in the trade “let it develop”

 

[MrGreedy]

If it's clocking and clattering on straight, but uneven/rutted roads, my thoughts would be drop links, ARB bushes or shocks.

Could be top mounts on the front suspension too. Forgot those before. Part not too expensive. But more expensive to change those due to labour and front suspension removal. If you were doing front shocks, get the top mounts done at the same time.

 

[Bellow]

Perhaps it might be helpful if I can record a sound file and upload it. I will see if I can achieve this!

A recording would very likely help.

 

[hamster8]

A recording would very likely help.

OMG! I managed to do a recording of the noises, then edit it, then only to find that I am not allowed to upload it here!

So now, I have uploaded to webspace! Here is the short video with the clanking in the background!

Sincerest thanks to all of you that are trying to assist! Much appreciated!

http://home.clara.net/hamster/public_html/CarNoises.mp4

 

[Bellow]

OMG! I managed to do a recording of the noises, then edit it, then only to find that I am not allowed to upload it here!

Fear not. someone will be along soon to advise how to post it. It's just that that someone isn't me.

 

[saff]

May be a long shot but I recently had an unfathomable knock/rattle on my E220. After much investigation it turned out to be a loose/broken plastic undertray. Easy cheap fix. You never know.......

 

[hamster8]

May be a long shot but I recently had an unfathomable knock/rattle on my E220. After much investigation it turned out to be a loose/broken plastic undertray. Easy cheap fix. You never know.......

Thanks for the suggestion but this model doesn't have one of those!

 

[Bobby Dazzler]

My shot in the dark is Anti Roll Bar bushes.

 

[geoffus]

Surely suspension, drop links, bushes and other obvious wear items should have been diagnosed by the three previous garages.
What about taking it for an MOT check ?