Help with Weird fuel line vibration/hum

[kwhelan 234]

Ive been trying to find an intermitant hum for weeks and have finally tracked it to the center of the 3 fuel lines running under the back passenger footwell. I thought it must have been a broken plastic clip and tried jamming pipes with soft rubber but it has made no difference and they look fine.its a high pitched hum and vibrates especially at the tank end.

Only thing i have found is

http://forums.bimmerforums.com/forum/showt...-after-starting

Has anyone come across this before .it seems to be gettng worse.what does the middle line actually do

[Michael. 2312]

Sounds like it could be a failed fuel pressure regulator diaphragm, so fuels leaking into the vacuum line making those sounds as bits of fuel are sucked through.

http://www.realoem.com/bmw/showparts.do?mo...hg=13&fg=10

Looks like it's on the back of the fuel filter. Part #13531436110

[kwhelan 234]

Sounds like it could be a failed fuel pressure regulator diaphragm, so fuels leaking into the vacuum line making those sounds as bits of fuel are sucked through.

http://www.realoem.com/bmw/showparts.do?mo...hg=13&fg=10

Looks like it's on the back of the fuel filter. Part #13531436110

thanks for that,can you explain the normal flow to a layman,im trying to get my head around the whole fuel flow system,it seems quite complicated with vacuums etc, apart from the noise obviosly the diaphragm will eventually fail and what then,will I be stranded?

it seems to be quite an irregular fault,people talk about pump failures a lot but this is quite a different ballgame

Edited May 19, 2013 by kwhelan