Humming & slurping sound

On my 1986 325es I have had a humming & slurping sound coming from my fuel pump area. I thought it was my fuel pump and had it replaced with a brand new Bosch fuel pump but the noise is still there. What else could cause this noise? Also there are times where the noise becomes more high pitch, which I think only happens when the tank is low but I don't know if that is a separate problem or not.

Electric fuel pumps DO make SOME noise. Is it the proper pump? Is it tight in the bracket? All the correct parts reinstalled? I never replaced the fuel pump in our '85 325e in the 20 years we owned it (but DID replace fuel hoses).


http://www.realoem.com/bmw/showparts.do?model=1254&mospid=47308&btnr=16_0172&hg=16&fg=15

Does the 'es have the in-tank pre-pump in addition to the outboard fuel pump? Which did you replace?

Fuel pressure regulator?

Is there a fuel pressure regulator? Maybe this is on the fritz.
Otherwise I might suspect the AC compressor/ expansion canister for those general types of sounds.

Chuck

Of course there is, but it's under the hood at the front on the fuel rail.
#6 here:

http://www.realoem.com/bmw/showparts.do?model=1254&mospid=47308&btnr=13_0233&hg=13&fg=15

Yes, which pump did you replace? The in tank pump or the external pump? If the in tank pump is bad the external pump may cavitate a bit trying to draw fuel from the tank.



http://www.realoem.com/bmw/showparts.do?model=1254&mospid=47308&btnr=16_0039&hg=16&fg=05

Sorry I mis-read..

I thought the original poster was talking about under the hood... but when I re-read it was "around the fuel pump area"... so my suggestions were all wrong.
When the one on my seven was going it made a lot of noise, mostly whirring/humming. When I replaced it shortly afterward a bug crawled up into the vent and sealed it off. This caused the tank to crush itself as it emptied, though I didn't notice until it started leaking. It was about 4-5 gal smaller by that point. In that tank because it was a "saddle" tank it had a siphon tube to move fuel from the drivers side to the passenger side. This siphon was powered by the bypass fuel from the fuel pressure regulator. Interesting piece of engineering.

Chuck