Strange buzzing noise

[johnnyroper]

Right car has developed a strange buzzing noise from offside relative to engine revs,hold it at 1800 rpm and you can get it to happen,when driving it happens around the same speed and again when revs dropping.

I have had a good look around nothing obviously amiss I cannot pinpoint noise when around the engine as engine noise drowns it out,whipped top cover off belt looks all good. It sounds like a vibrating panel but I cannot see one.

Anyone else had this happen and if so what was the cause?

[Chrispb]

Check that plastic trunking air intake pipe that goes through the inner wing panel.

[johnnyroper]

Cheers Chris will take a look at that later.

[insanitybeard]

That sounds similar to a noise I get (and have never got to the bottom of) which sounds like a resonance which comes from the driver's side of the engine bay when holding a constant throttle, I've never made a note of whether it's always at the same revs but will make a conscious effort to take note now. I had wondered previously whether it was related to the tensioner on the alternator belt but I replaced mine (for another reason) and it made no difference, and I know my alternator freewheel pulley is working properly so......... I dunno!

[johnnyroper]

Sounds like you could have similar resonance to what I have got.
Finally Got few days off next week so gonna sort injector seals and have a look for source of this noise. If I have any success I will let you know.

[insanitybeard]

Does yours make the noise whilst static as well or do you have to be moving?

[johnnyroper]

It does it static if I hold revs at 1800,also when revving through 1800 going up or down,it seems more pronounced when under load.

Forgot to say I have proved everything on drive belt as I took off to test it out,although that was a shot in dark as it certainly sounds more like parts vibrating against against something else.

[egg]

I had the same noise on my other car at 1450 rpm. Turned out to be heat shield vibrating against the exhaust.

[insanitybeard]

I can't get the noise to occur with the engine running but the vehicle stationary either by holding the revs steady at a constant throttle or by steadily increasing or decreasing revs so the noise I experience must be unrelated to your issues. As the noise I hear only seems to happen under load I've wondered if it could be related to turbo spooling but in my case it does sound like a resonance and it does occur on a constant throttle- but only under load apparently.

[johnnyroper]

I can't get mine to do it at all now no matter how hard I try,very odd.
Also I am not going to be looking further unless it starts again as not doing injector seal work now,keeping the seals and bolts for when I change head on the Audi I have purchased

[johnnyroper]

Well it seems my buzzing noise is temperature related as I only noticed in the extreme temps last week and then it stopped happening.
Yesterday I took kids around safari at longleat so was at idle/crawling along for long periods and it started again,once we had parked for a couple of hours it stopped again??