bad metal sounding vibration in high revs

[senninha1981]

I have a metal vibration/buzzing sound over the 4200rpm mark,
I have had a good lock underneath all heatshields are sucure and no vibrations and nothing else seems a miss.
Its sort of under the rear seats underneath the car where its coming from.
Any ideas
I thought it might of been the fuel pump as its sort of a metallicy sort of buzzing sound?

[gasketface]

Could be many things but does the rear mounting for the centre section of the exhaust hit the brace ?.I mean the one towards the rear of the car that has two rubbers on it ?.Check the rubbers.

[senninha1981]

no all is fine in that department

[tshirt2k]

Are you sure you're not confusing it with pinking? Or detonation

[stainesy]

Are you sure you're not confusing it with pinking? Or detonation

what is pinking?

[gasketface]

http://www.golfgtiforum.co.uk/index.php?topic=205162.msg1908804#msg1908804

[senninha1981]

Are you sure you're not confusing it with pinking? Or detonation

No coming from the back under the seat area

[senninha1981]

could it be the fuel pump being under load at certain rpm making it sound a metalicy rattle, do they have problems?

[tshirt2k]

Probably a heat shield.

[gasketface]

Check your heatshield above your backbox.It's held on by round retainer thingies (  ) that corrode and fall off (as one of mine recently did).They are used widely on VW's,it's the same part that holds the plastic power steering pump/belt cover on.