Help with mystery noise

[Patrick Daines]

I've done lots of searching but to no avail. Ever since buying the car there has been what I assume is an exhaust noise.

I have standard cat and K-tec 2.25 inch catback

From 2.75k rpm up there is a whistle almost rasp (not the good kind) more prominent with harder throttle.

Then in the upper revs it turns into an almost tinkling sound.

So far I've replaced all gaskets and bolts ( cat to manifold sprung joint with genuine Renault kit, olive joint has new beefy clamp on and high temperature sealant, two rear sleeve joints have new clamps)

I've also replaced all the exhaust mounts and checked all the heatsheilding (washered a few loose ones) but still the noise persists!!

It doesn't do it in neutral when I try and replicate it on the drive also.

Anyone have any clue?!?!?

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[E11OOT]

Crack in the exhaust manifold or need a new exhaust/header gasket (at the engine)?

 

[bozothenutter]

A search on exhaust whistle should have brought up the gasket mate.....

 

[botfch]

If it’s not the manifold to cat joint then it’s probably the olive joint they are a nightmare to seal unless you get the cat sleeved.

 

[Patrick Daines]

Definitely not either side of the cat joints as they are sealed solid now. Checked over each component for cracks etc but can't see anything obvious.

I can't say I can be bothered to remove the manifold and replace a gasket there. Doesn't sound like it's that far up either tbh.

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[Patrick Daines]

So I had the olive joint cut out and welded today..... still makes the noise.

I have a genuine Renault cat to manifold gasket kit brand new fitted and new clamps on the cat to midpipe sleeve and midpipe to back box sleeve.

One of these 3 is still causing the problem as whenever I play around with them and take it for a drive the volume of the noise will have changed.

Both sleeve joints have high temperature sealant in them and clamped up solid. Anymore I can do?

Maybe replace the U clamps with the band style??

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