Unusual Rattle/Noise - can anyone help please?

[Cakesparky]

Hi all,

My beloved SL 500 (2002) has developed a loud rattle/scraping noise when the accelerator is depressed. Not exclusively then, as it also does it when 'freewheeling'.
(54,000 miles on the clock - recently had full service.

The noise is definitely NOT from the engine block.

A Mercedes dealer diagnosed that a piece of the Cat material had broken away and was rattling around loose - as a result I had 2 after market Cats fitted and the noise seemed to stop for a few days.

Now the noise is back - I'll describe it as best I can.
It's like a piece of loose metal is either trailing the ground (I've checked and of course it's not) --- or like a small piece of metal or debris inside a drum rattling round....It most commonly occurs when gears are engaged, but also does it when standing idling in neutral.

I'm in the middle of a grand tour of Europe and have a 1000 mile journey home in the next few days - and want to be reasonably confident it's not a terminal fault!! At least it might make it home to my local workshop!

Can anyone suggest any possible causes?

Thanks!

 

[Tinkerer]

I had something very similar to that and when I took it to my local indy he informed me, with a big grin on his face, that I had a loose exhaust pipe clamp! £10 and it was like a new car .... sorted!

 

[BTB 500]

There's a known issue with the R230 where a baffle comes loose in the fuel tank, rattling around. Could it be that?

 

[Cakesparky]

Thanks guys - I'll have them both checked out when get back to Blighty!

Any other suggestions all very welcome....

 

[BlackC55]

I would be looking at the cats again. Cheapo non gen cats are just not worth it IMO.

 

[BTB 500]

Surely even aftermarket cats wouldn't fail after 2 days ?

 

[Cakesparky]

No, don't think it's the Cats failing - suspicion is a mis-diagnosis by the Merc guy, and I've shelled out £800 on 2 cats it probably didn't need!
Will know more when I get back to UK from Monte Carlo... Expensive enough place without breaking down here...

 

[AMG19]

Exhaust pipe clamps and the chumps that fitted the 'mickey mouse' exhaust cats didnt buy a new fitting kit?