W202 Exhaust Resonance

[Merc808]

Dear Friends,
I have a 1996 N, W202 Diesel, Elegance auto. I have an awful resonance coming from the exhaust ( down pipe area ) at around 1500 to 2000 rpm, under load. I have recently had a new back to front exhaust fitted by the main dealership. I took it back after a month and they replaced it free of charge. It still resonates as before so I don't believe it can be the new exhaust, although the old one didn't do this. I have had a brief look underneath but everything looks OK . The exhaust is secure and doesn't appear to rattle. The sound comes from the front so I don't believe its a loose Cat Converter. It's driving me mad . Any ideas ? ( sorry posted in wrong forum )

 

[sym]

Moved to correct forum !

S.

 

[se97mlm]

mine did this at around 3000 rpm, turned out to be the poly v belt tensioner had worn out. sounds just like a metallic exhaust resonance sound.

get someone to rev the engine while you look at the tensioner, you should see it wobble like crazy at the resonance point if that's what it is