Rattle at >3000rpm

[robert_n]

My car has a rattle that starts when the engine speed is just over 3000 rpm. To me it sounds like a loose washer type nose. The noise is nearly non existent when the car is cold but is quite loud when the car has been for a run (it can only really be heard stationary in neutral road/wind/engine noise block it out while driving).

From crawling around under the car when on stands it sound to me like it is from the transmission tunnel at just behind the front axle kind of area, but nothing was visibly loose.

Any suggestions before i start taking bits off or worse paying some one else to take bits off and have a look .

Thanks,

Robert

[A80Avant]

maybe it is the propshaft again...

[robert_n]

Again? (Are you confusing me with someone else?)

Can it even be the propshaft if it is not spinning? (I hear the noise best stationary in neutral)

[A80Avant]

the again was because recently someone else had the same culprit.

If it also does it stationary then it is most likely that it is something else,maybe something loose.

[RustyNut]

Exhaust heat shield?

[denniselbows]

it not a rattle in one of the exhaust boxs is it might explain why you can't find anything loose and also maybe why it olny does it when hot. i have heard about the insides breaking and rattle around abit just a thought

[Error404]

clutch release bearing?

[Sonic]

Ive had a similar one for a while, im sure its the exhaust rattling against something down by the front axle... for some reason it only does it when its been for a run also!

[robert_n]

it not a rattle in one of the exhaust boxs is it might explain why you can't find anything loose and also maybe why it olny does it when hot. i have heard about the insides breaking and rattle around abit just a thought

A few other folk i know suggested it could be the cat like you suggest but got a friend to rev the car while i was under it and tried to see if i could feel a vibration from the exhaust and had no luck. Hence why i thought i could be in the transmission tunnel.

Thankfully it does not seem to be an imminent huge issue as its done a couple of hundred mile in that state. Sounds like investigative surgery is required then.

[macspring]

I would have also said

it was the exhaust heat shield on the down-pipes. I'm assuming it's an ABY.

Kind regards.

[alg]

Had same issue on RS2 when I first got it. There is a long thread somewhere. Propshaft centre bearing.It vibrates in neutral. Bet it gets worse sitting in neutral at about 3-4k & rapid on/off throttle. Metallic rattle.

[robert_n]

Thanks for the suggestions.

I've taken a bit of time to get round to thinking about this again but I have a couple of questions about some of the issues mentioned.

If it is clutch release bearing or propshaft centre bearing what are the implications of doing nothing about it?

Whats the best way of checking which of these two issues it is? (if either, downpipe heat shield should be easier to check)

[Ducky]

If you press the clutch in does the noise disappear...if not then I doubt its the release bearing.