Vibrating/Resonating exhaust (Griff/Chim)

[lazyitus]

Have you ever...

had a resonating/vibration from underneath the car at a certain level of revs as you drive through the gears? I think it's the exhaust making this sound, even though its fit is nice and snug ?

How did you resolve this issue ?

T.I.A

[clive f]

I know what you are putting up with, you need to try and identify which area of the car the noise is coming from, drive around and find the rpm where the noise occurrs, then try and pin point it as best you can, then jack it up, get underneath it and inspect everything, it may just be a loose bolt rattling around, good luck.

[lazyitus]

Cheers Clive. Gonna have a good root round on Saturday.

[bigdods]

is it sleeved ? if so and the wadding wasnt put back in it will resonate quite badly.

Mine is sleeved with wadding in and i still get resonance at ~ 2500 rpm. |As long as I'm above, below or driving thrugh that rpm its fine. But if I happen to be dawdling in high gear it does resonate. I just avoid hanging around at 2500 :-)

[knight]

Had an annoying rattle from the exhaust last month, turned out to be one of the lambda sensors was only finger tight, a quick tweak and it went

[lazyitus]

bigdods said:

is it sleeved ?

No, it's currently standard spec.

[paulathome]

Check the rubber mounts on the main exhaust centre bracket. If some one has tightened the bolts up too tight it squashes them so much that they have no effect and cause metal to metal contact and hence vibration. (I know from experience)
On mine it caused a vibration between 1600 and 1800 RPM and then disappeared.
Paul.

[Cerberus90]

A resonance can be impossible to get rid of. It may be resonating at the natural frequency of the steel.

My dads got this in his T350. Everything is mounted properly, securely and in good condition, but it still resonates at 2500rpm in 4th and 5th under a about 25% load.

As I've said, only way to deal with it, change gear or give it a boot full to get out of the resonating area,

[JKY]

MY Griff does it too. Did it pre exhaust mods, post mods, new rubber mounts, manifold and exhaust been of a few times for different reasons, both bolt hole positions on block tried, but no matter what I do it is always there. Only does it at about 2000 revs and, as mentioned by others, it is a resonance that maybe cannot be removed.

[lazyitus]

Thanks all - will check the rubber mounts tomorrow and report my findings.

[Clippy]

Could be the nearside exhaust manifold 'rubbling' on the chassis - happpens...

Tweak the engine over to the right a little witht the mounts loostened off or shim the nearside mount out a little...

G