Exhaust Rattle at certain revs

[Monkriss]

Okay so i got my car in september. In February the exaust started to rattle at 1.9k revs and 3.5k revs. I went to the garage and they said the centre silencer is breaking up so they fit a new one.

A week later the problem was still there. they said it was the centre silencer. so they replaced it for free because it had only lasted a week.

I had no problems until about 3 weeks ago (4 months since last silencer) when it started to rattle at those revs. so i thought, must be the centre silencer again?
I replace the centre silencer and the problem went. now 1 week has passed and would you have guessed it. its rattleing again.

Makes me think, is it actually the silencer. and surely if it was breaking up, it would rattle no matter what revs it is. It must be some kind of resonating frequency at 1.9 and 3k revs.

What could be causing the rattle?? im tempted to remove the centre silencer completely and put a straight through pipe. but want some ideas first.

The rattle noise itself, it sounds like a hollow buzzing noise. and no my exaust isnt blowing. ive heard blowing and it sounds completely different

hope someone can help
Cheers

 

[Monkriss]

oh and, inbetween the revs that causes the rattle. the exaust sounds fine and has no problems

 

[CupraSean]

Sure it's not knocking mate ? I think Most mk3's have exhaust knocks lol

 

[Olly20VT]

A loose heat shield? Maybe it gets pushed back when you've changed the bits and then comes loose again after some driving, I would get under there and wiggle everything. I've had it on mine and my wifes A3

 

[Monkriss]

yeah i got that knocking problem too.. the exhaust slips on a rubber part and bangs against my car. very annoying but i cabletied it and it seems okay for now.

yeah might take it down to the garage today and ask if my heatshielding is loose cheers

 

[chris1788]

mine rattled near centre silencer there is a metal plate that goes across and it rubbed on there, fitted few spacers to move away from exhaust problem solved