Where is the noise coming from????

When the car is turning over, the revs fluctuate around either side of the 1 on my rev counter and a whine/sucking noise comes from the fuel pump area ( in front of the rear wheel) but when I put me ear there, it's not the fuel pump but a square box thats on the side of the fuel pump. Can anyone please tell me what this part is and what might be causing the noise? Many thanks for your help

Are you on about the Airbox AKA airfilter?

the square box is the fuel pump housing

the item behind that is the accumulartor

hth

sounds liek the fuel reservoir to me. the accumulator is a metal cylinder near the tank with 2 fuel lines on the same end, fuel pump is metal cylinde inside a foam square in a metal cradle next to the tank with a fuel line out of each end. reservoir has something like 4 fuel pipes connected to it

Jacked the car up and found that the noise came from the fuel pump, very loud buzzing, I can hear it over the engine when running. I have replaced the fuel pump with a brand new one BUT IT STILL BUZZES!!!!! Still hear it above the engine. I've got about £10 of fuel in her. She's a 88 GTi cabriolet if anyone can help. Afraid of running her incase I do more damage. Some mention fuel lifter??? Might go in to tank from under the rear seats to see if any crap in bottom and clean the internal filter. Any help will be fab so I can try all your advice out tomorrow on my day off. Thanks guys

I thought all fuel pumps were noisy?? Mine certainly is!

Surely not to the point where you can hear it over the engine turning???? Its driving me nuts!!! Is it safe to go in to the tank from under the rear seats?

You can hear mine running over the engine, I was told it was fine.

Do you have the foam insert in as this reduces the buzzing slightly?

Do you mean the foam that was around the pump before I inserted it in to the rubber case? If so, yes its on. My friends cabriolet, no pump noise only when it primes??? Think I'll change the filter tomorrow also. Could the pump have been wired wrong or is there no + and -?

no you shouldnt be able to hear it over the engine!  
check your in-tank lift pump. this keeps the main pump supplied with fuel and if  it packs in the main pump has to strain hence the very loud buzzing. disconnect one of the wires to the main pump then turn key 1 click, should hear the in-tank pump prime. unless yours doesnt prime on the key, otherwise you'll have to crank it over. be harder to hear the lift pump tho!

its under the rear seat and accessible once you remove the black metal plate

With regards to your post "rubjonny"- I'm in the middle of getting the lifter pump out to clean it and check it over but I cant twist it loose. How can I twist it and what have you used in the past? Was thinking a bit of heat but to close to the fuel for my liking!!!!
Cheers for your help guys

Done as you advised and discnnected one wire from the in-line fuel pump, turned the key 1 click and guess what…… The bloody thing primed which means it's something else but what?????

could be the mesh filter on the end of the pump that has got blocked. on my mk1 the pump came out pretty easily and also same story on our mk3 polo. just lucky I guess!

just a case of finding something which will get you the leverage you need, as you say heat there wouldnt be a good plan!

Been at it all morning trying to twist the bloody pump, NO GO!!!! Must be the lift pump tho as the problem is from the in line fuel pump back to the tank! Makes sense that the noise is the in line pump struggling! Fancy a trip to North Wales rubjonny to give it a go??lol

Finally got the lift pump out! The filter was very clean and to be honest, looked like new. But when I flashed a torch inside my fuel tank, I found a lot of rust particals on the bottom but none on the lift pump filter. So why is my in line pump noisy and what course of action would you guys take???? I intend on changing my filler neck next week. Anyone suggest where to get the necks from?
Cheers

ok next step would be to test the lifter pump actually works, run a long piope from the output pipe and point it in a bucket, turn key 1 click and make sure it sprays out a nice burst of fuel. fuel is handy to keep for cleaning stuff up, or if the container is clean just pour it back into the tank!

sorru rubjonny, do you mean the outpipe on the bayonet fitting that I had trouble twisting? What bore pipe do I need?

if you look at the lift pump there are 2 pipes, they should have arrows on to show flow direction, run a long pipe from the one with the outward arrow on. or if unsure, lift it out again, the output pipe is the one attached to the end of the lifter pump

drop pump back in tank, point this pipe into a bucket and tuern key 1 click, the lifter pump should spray out a nice jet of fuel

excellent cheers rubjonny! I'm off to dentist for 2pm so will get some hose on way back and I'll give it a go when I get back. I'll pm if thats ok save hammering the forum? Thank you very much for your help. find it much more rewarding when you do your own work and people like you to help.

best to post up in here then anyone else can chime in if they have ideas as well