Fuel pump noise

buddrinker · 01-23-2015, 04:39 PM

Hello been awhile since I have been on this forum. I have a louder than normal hum coming from behind seats when ignition is turned on. I believe its the fuel pump. The noise use to quit once the engine started but now it stays humming when engine is running. Does this mean the fuel pump is on its way out? Engine still runs good no performance issues. No dash lites lit up(not sure if it even has one for fuel system)
Thanks for replys.

DerekSelmanRacing · 01-24-2015, 11:36 AM

I can't really help, but I'll give you my experience so far. Mine started making noise occasionally a couple years ago. BMW had a TSB out claiming the noise is caused by a bad pressure regulator which is located in the tank adjacent to pump. Changed my regulator---no joy. Car still makes noise sometimes, still seems to function normally. I'll be watching this thread because I'd actually like to fix mine before it leaves me stranded.

buddrinker · 02-14-2015, 03:10 PM

Anyone?

WAMz4 · 05-05-2015, 01:12 PM

I have an electrical "motor sound" coming from below\between the seats. I guess you could call it a "humm" but it isnt steady, just a sporadic electrical motor sound.
I had the dealership check it out, and they say it is the fual pump.
They also say the pump can make this sound for years without going out.
To that end they say replacing it is only covered under warranty if it actualy goes out, not when it just starts making noise.
So I guess I have to actually be stranded on the road before they will cover the cost to replace it.

RADRACR · 05-05-2015, 01:55 PM

Quote:

Originally Posted by WAMz4

So I guess I have to actually be stranded on the road before they will cover the cost to replace it.

Pretty much. The rear a/c fan in my X5 is squeaking, indicating the bearing is on its way out but of course they won't fix it until it fails. That's why I never buy the extended warranty. The parts actually covered (major engine and trans components) under the warranty are extremely unlikely to fail in the first place. Great scam they have going for the uninformed owner with too much money.

gas-can · 05-06-2015, 09:41 AM

Plus remember that you are sitting right on top of the fuel tank and pump. You will hear the pump a hell of a lot more with these than those with 4 seats.

Mine gets louder as the fuel level drops- makes sense I suppose; less fuel, less stuff to absorb/deaden the pump waves/noise.

I wouldn't worry about it.

-gc

RADRACR · 05-06-2015, 10:17 AM

As if it knew I read this thread a couple days ago, my car has now started making noise in the fuel tank area pretty much constantly as long as my foot is on the throttle. Then is quiet when I brake to a stop. Then starts again when I'm driving.

About a month ago, I smelled gas in the cabin and got a CEL. Took it to my regular indie shop to read it; and it was something to do with the pump (I forget specifically). He cleared it and it never happened again (no smell). Still no CEL -- but is this the time to get it fixed? I was quoted $450... something I don't really want to do if the car still drives ok.

trevor · 05-19-2015, 04:42 PM

If you got experience and the tools - open up the engine and clean it, you will find the issue.

No experience? Take it to a reputable european car shop (yelp it).

RADRACR · 05-19-2015, 04:47 PM

Quote:

Originally Posted by trevor

If you got experience and the tools - open up the engine and clean it, you will find the issue.

No experience? Take it to a reputable european car shop (yelp it).

What do you mean the issue will be found? What is the issue? And what does the engine have to do with a noise in the rear?

buddrinker · 06-23-2015, 02:26 PM

Fixed my fuel pump noise if anyone has the same issue. Used a gas additive that lubes the pump. Cant remember what it was called. Got it at a bumper to bumper. Took about a quarter of a tank of gas then the noise disappeared. Its been about a month and the pump is still quiet.

buddrinker · 07-24-2015, 11:22 AM

The oil additive I used was lucas gas and diesel treatment. Its an injector cleaner but also lubes the fuel pump. The cause was to dry of fuel. I was fueling up at places with ethenal because I could get 94percent octane. Have not had a problem since. Will stay away from ethenal fuel.

unluky · 08-01-2015, 05:11 PM

Why were you looking for 94 octane? You running a supercharger?

01-23-2015, 04:39 PM	#1
buddrinker Enlisted Member 4 Rep 42 Posts Drives: Bmw Z4 3.0i Join Date: Jan 2008 Location: Alberta iTrader: (0)	Fuel pump noise Hello been awhile since I have been on this forum. I have a louder than normal hum coming from behind seats when ignition is turned on. I believe its the fuel pump. The noise use to quit once the engine started but now it stays humming when engine is running. Does this mean the fuel pump is on its way out? Engine still runs good no performance issues. No dash lites lit up(not sure if it even has one for fuel system) Thanks for replys.
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01-24-2015, 11:36 AM	#2
DerekSelmanRacing Second Lieutenant 8 Rep 222 Posts Drives: 05 Z4 3.0 SMG, 01 530 Join Date: Jul 2008 Location: Lake Havasu City, AZ. iTrader: (0)	I can't really help, but I'll give you my experience so far. Mine started making noise occasionally a couple years ago. BMW had a TSB out claiming the noise is caused by a bad pressure regulator which is located in the tank adjacent to pump. Changed my regulator---no joy. Car still makes noise sometimes, still seems to function normally. I'll be watching this thread because I'd actually like to fix mine before it leaves me stranded.
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02-14-2015, 03:10 PM	#3
buddrinker Enlisted Member 4 Rep 42 Posts Drives: Bmw Z4 3.0i Join Date: Jan 2008 Location: Alberta iTrader: (0)	Anyone?
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05-05-2015, 01:12 PM	#4
WAMz4 First Lieutenant 45 Rep 384 Posts Drives: 2006 Z4 3.0si Roady Join Date: Mar 2009 Location: Denver CO iTrader: (0)	I have an electrical "motor sound" coming from below\between the seats. I guess you could call it a "humm" but it isnt steady, just a sporadic electrical motor sound. I had the dealership check it out, and they say it is the fual pump. They also say the pump can make this sound for years without going out. To that end they say replacing it is only covered under warranty if it actualy goes out, not when it just starts making noise. So I guess I have to actually be stranded on the road before they will cover the cost to replace it. __________________ The Internet said it. I believe it. That settles it!
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05-06-2015, 09:41 AM	#6
gas-can Second Lieutenant 25 Rep 204 Posts Drives: 2006 3.0i Roadster Join Date: Oct 2012 Location: USA iTrader: (0)	Plus remember that you are sitting right on top of the fuel tank and pump. You will hear the pump a hell of a lot more with these than those with 4 seats. Mine gets louder as the fuel level drops- makes sense I suppose; less fuel, less stuff to absorb/deaden the pump waves/noise. I wouldn't worry about it. -gc
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05-06-2015, 10:17 AM	#7
RADRACR Captain 84 Rep 924 Posts Drives: '08 Z4 M Coupé // '09 X5 d Join Date: Apr 2010 Location: Sioux Falls, South Dakota iTrader: (2)	As if it knew I read this thread a couple days ago, my car has now started making noise in the fuel tank area pretty much constantly as long as my foot is on the throttle. Then is quiet when I brake to a stop. Then starts again when I'm driving. About a month ago, I smelled gas in the cabin and got a CEL. Took it to my regular indie shop to read it; and it was something to do with the pump (I forget specifically). He cleared it and it never happened again (no smell). Still no CEL -- but is this the time to get it fixed? I was quoted $450... something I don't really want to do if the car still drives ok. __________________ '08 Z4 ///M Coupé (#1765/1815) — 1 of 68 Sepang Bronze / Black Nappa / Madeira Wood / 1 of 1 this combo 19" Advan RS / AP Racing / Bridgestone RE-11 / Autosolutions SSK / R.E. Diablo / R.E. trans mounts '09 X5 35d — Space Grey / Saddle Brown 20" Forgestar F14 / SCR Delete
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05-19-2015, 04:42 PM	#8
trevor New Member 2 Rep 28 Posts Drives: 2005 BMW Z4 and 2001 BMW 515i Join Date: May 2015 Location: Washington, D.C. iTrader: (0)	If you got experience and the tools - open up the engine and clean it, you will find the issue. No experience? Take it to a reputable european car shop (yelp it).
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06-23-2015, 02:26 PM	#10
buddrinker Enlisted Member 4 Rep 42 Posts Drives: Bmw Z4 3.0i Join Date: Jan 2008 Location: Alberta iTrader: (0)	Fixed my fuel pump noise if anyone has the same issue. Used a gas additive that lubes the pump. Cant remember what it was called. Got it at a bumper to bumper. Took about a quarter of a tank of gas then the noise disappeared. Its been about a month and the pump is still quiet.
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07-24-2015, 11:22 AM	#11
buddrinker Enlisted Member 4 Rep 42 Posts Drives: Bmw Z4 3.0i Join Date: Jan 2008 Location: Alberta iTrader: (0)	The oil additive I used was lucas gas and diesel treatment. Its an injector cleaner but also lubes the fuel pump. The cause was to dry of fuel. I was fueling up at places with ethenal because I could get 94percent octane. Have not had a problem since. Will stay away from ethenal fuel.
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08-01-2015, 05:11 PM	#12
unluky Major 7519 Rep 1,247 Posts Drives: 04 z4 3.0 Sport & 15 X5 35i XD Join Date: Aug 2013 Location: Sedalia, MO iTrader: (0) Garage List 2015 BMW X5 XDrive 35i [0.50] 2004 BMW Z4 3.0 Spo ... [0.00]	Why were you looking for 94 octane? You running a supercharger? __________________ 2015 X5 XDrive 35i - 2004 Z4 3.0 Sport
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