Noise at 2000 revs

Ive started getting a noise on my Elise around the exhaust. I only get it when the engine has been warmed up and only when accelerating or decelerating at approx 2000 revs. I thought it was the exhaust blowing but surely it would do it all the time if that were so?
My local dealer had a quick look at it and thought it may be a crack in the manifold which expands when warm.
Has any body else had anything similar or got any ideas what it may be?
Thanks in advance

If it comes from the silencer part, it may be a loose baffle inside.
It only resonates at certain frequencies and will get louder with time.
Change exhaust when it becomes unbearable.

I fit comes from the manifold side, you may need the anti-tizz bracket (don’t know how it is but the dealer should). But anyway, I don’t think it could be a cracked manifold, it would be Loud then, not like a rattle.


check undertray under both seats.
It happened to my car…everybody thought it was coming from the exhaust.

Mine started doing exactly the same thing after the Cat was put back on for the MOT.
After my local dealer had charged me an hours labour to re -jig the exhaust (Which I ended up re-doing myself properly)they couldnt find a thing and said it was the baffles in the exhaust and nothing could be done about it!!!
I had already tried taking both undertrays off and drove down the road and the noise was still there!
About 6 months later my original exhaust fell off so I had to replace it and hey presto…
The noise was still there
Anyway, through talking to loads of people this was what I found… And I never cured mine. Just bought an Exige

  • The Anti tizz will only stop the resonance from happening in the first place, and probably wont cure the noise once its started. But as I said to my dealer, Your never going to fit it in the first place if you havent got a noise!!!

  • All fingers pointed towards the manifold / downpipe flexi pipe, which in my car had been disturbed when fitting the Cat.
    Moto-build sell cheaper replacement downpipes but told me to try putting 2 large Jubilee clips around the Flexi bit and see first if this stops it. If it does then you could either fit a new manifold or simply leave the jubilee clips in place

I never bothered, just put up with it.


This may help.

I had this once - it turned out that it was the HOT exhaust rattling against the undertray where the aperture is (i.e. the bit where the exhaust sort of pokes through the undertray).
The thing is, you cannot detect this when the engine is COLD but as the exhaust heats up it expands just enough to touch the undertray and ‘zizz’. Or it did on my car - some gentle re-profiling of the aperture cured the problem.