Pinking noise

[Jos]

Hi all,
Recently purchase a 97' C200 estate and I love it!
There is a tinkling noise that sounds a bit like pinking but can only heard if you listen carefully under hard acceleration. I changed the air filter and plugs recently and if anything I would say it was running a bit rich - fitting the new air filter I hope will cure that - so I don't think its is pinking. Fitting the new filter and plugs made no difference. Has anybody had anything similar or any idea what it could be - I have heard of loose baffles in the CAT could make rattling noises??
Secondly I am borrowing my parent’s caravan soon and was wondering if there was any thing to keep an eye on or check before towing - engine and gearbox wise?

Many thanks for a fantastic resource.

Paul

 

[fnkhan68]

read the section ''loss of power''

 

[stwat]

This could be the manifold leaking slightly or from where the down pipe joins the middle section. I hear quite a few C classes rasping and it does sound a little like pinking. My 190 also does it but I've never got round to fixing it.
(note to self, stop being a lazy sod!!!)

Stu

 

[Jos]

The car towed the caravan superbly, apart from the pinking which was worse with the increased load. I have looked for any split vacuum pipes and leaks but have not found any. I have however disconnected the MAF which made no difference at all, so I intend to replace that ASAP and may be that will also fix the pinking problem.

 

[Jos]

Bought a new MAF from e-bay for £125 and this seems to have fixed the pinking problem - car is also alot more responsive and changes gear better.

Thanks to all who offered advice.