clunking knocking noise from under car

[dan f]

Hi.
I have a 2002 R170 SLK.
I have noticed 2 unusual noises.
One seems to be coming from in front of the bulkhead on the passenger side near the floor, and the other seems to be coming from the area just above and behind my left ear when sat in the passenger seat.
the front noise only seems to happen over uneven large bumps, and the rear noise happens on uneven roads, but not when the suspension would be compressing but a second or so after and only seemingly on lateral type movements such as going round a corner and over a bump.
The front noise sounds like a low pitched clonk and the rear noise sounds like a muted 'click' or 'click-cli-click' sort of sound. (Difficult to describe).
Never heard noises like this in our previous SLK.
Any one any ideas? I rue the day I decided not to listen to music and leave the radio off. Now I know the noises are there, I find myself listening for them.
Thought about taking it to the stealers, but would like some ideas first if possible.
Cheers all,
Dan.

 

[grober]

my guess

My guess would be.
Front noise possibly suspension related or possibly loose exhaust. Try bouncing the car up and down by hand on the nearside front to see if you can elicit it.
The rear noise might be emanating from the hardtop mechanism as the body flexes/relaxes. Your new AMG SLK might have stiffer suspension/ lower profile tyres than you previous car which might cause this.

 

[pammy]

My guess would be.
The rear noise might be emanating from the hardtop mechanism as the body flexes/relaxes. Your new AMG SLK might have stiffer suspension/ lower profile tyres than you previous car which might cause this.

Can't say I've ever experienced this with mine and while not AMG - I'd be worried if the car was flexing around that roof.

I'd be looking at springs, suspension etc How many miles has it done - iirc it's not very many - but I might be thinking of another

 

[Bobby Dazzler]

My guess would be.
Front noise possibly suspension related or possibly loose exhaust. Try bouncing the car up and down by hand on the nearside front to see if you can elicit it.
The rear noise might be emanating from the hardtop mechanism as the body flexes/relaxes. Your new AMG SLK might have stiffer suspension/ lower profile tyres than you previous car which might cause this.

Would be my guess(es) too.

Other thought regarding click behind you - is there a storage bin between the seats - could it be coming from there?

 

[dan f]

Hi All.
Thanks for the suggestions.
I have done some more checking and 'poking around' this evening and I think the front noise is coming from the steering.
Are there rubber bushes on the steering components that wear?
I think another possible cause may also be the stabiliser bar (anti-roll bar).
The rear noise may be down to the adjustment of the door catch or the boot lid. I will investigate further.
It isn't coming from between the seats but to the left when you are in the passgenger seat. When in the drivers seat it seems to come from just behind the passengers head.
Any more ideas or indeed advice from anyone who has had a similar experience, greatly appreciated.
Many Thanks,
Dan.

 

[Dieselman]

I'd go for front anti roll bar link and roof folding mechanism.
Try rocking the car side to side and listen for the fron knock, classic sign of anti roll bar links.
The roof mechanisms do wear and cause rattling.

 

[dan f]

One thing that I have noticed is that the rear noise doesn't seem to happen when the roof is down, however I may just not be hearing it as there is a lot more noise with the roof down.
The roof seems just as sturdy as our old car whe I checked the mechanism, so I don't think it is wear, it does sound like something is loose, but in a clicking against plastic sort of way (only way I can describe it...)

Cheers,
Dan.

 

[Bobby Dazzler]

I have done some more checking and 'poking around' this evening and I think the front noise is coming from the steering.
Are there rubber bushes on the steering components that wear?

Do you get any 'feeling' through the steering? Loose feel, knocks, vagueness, vibration, etc?

 

[dan f]

Do you get any 'feeling' through the steering? Loose feel, knocks, vagueness, vibration, etc?

Hi.
No, that is the weird thing.
Had a new steering damper fitted when I bought the car as it was leaking, and it completely transformed the steering feel, but I don't think that is it, do you?
Booked into the stealers now in a week or so.
Will report back if they find/fix anything.
Dan.

 

[Bobby Dazzler]

Had a new steering damper fitted when I bought the car as it was leaking, and it completely transformed the steering feel, but I don't think that is it, do you?

Difficult to say. It took the dealer a while to correctly identify the cause of a loose shake I could feel through the steering wheel - turned out to be some slack in the steering column, but they swapped lots of stuff before they worked it out.

Had a thought about the clicking. Is it coming from the upper seat belt mounting point. I've had clicks originating from the adjustable mechanism on a few cars now. They swapped something on the ML and it has now gone away (said hoping not to count chickens!!).

If not fixed by then, and if Gazz comes along to the mini-meet then he may have some ideas - he has an SLK, is very knowledgable about all things MB.

 

[dan f]

If not fixed by then, and if Gazz comes along to the mini-meet then he may have some ideas - he has an SLK, is very knowledgable about all things MB.

Sounds like a plan.
My dealer is usually very good at finding and fixing these sorts of things, but we shall see.

 

[dan f]

Hi all.
The tech at the dealers was very helpful and has checked and lubricated all the parts of the roof and checked for security. I haven't heard that noise again yet.
They also fixed my drivers door window that wasn't going up quite far enough and giving a bit of wind noise. Cool.
As for the noise under the car on the nearside at the front, turns out one of the spot welds on the wing panel near the door at the bottom had come apart and was very noisy. Driving over undulating bumps would have flexed it enough to cause the noise.
It has been rewelded, and no more noise! They did seem to have
tightened the steering etc up too, so that can only have helped.
Cheers,
Dan.

 

[Bobby Dazzler]

Sounds like a successful trip to the dealers ;0