Puttering Noise From Rear Of 2004 S4 Prior To Start - Fuel Pump?

**Rennspeed** · 10-13-2010 04:46 PM

Recently when I turn the key to the accessory "ON" position prior to starting I get a puttering noise from the back of my 2004 S4 (Like the noise a fuel pump might make priming prior to starting the motor)

My other two B6 S4's never made this noise, and this 2004 B6 S4 only recently developed this symptom.

Does anyone have an idea what could be causing this racket?

Any and all input would be greatly appreciated!

Renn

**B6JoeS4** · 10-13-2010 06:11 PM

1. How many miles are on the car
2.Has the fuel filter ever been changed

**Rennspeed** · 10-13-2010 06:29 PM

Joe,

I think you hit the nail on the head.

It has 136,XXX, and no the fuel filter has not been changed during our time with the S4.

**B6JoeS4** · 10-13-2010 07:36 PM

Oh wow that a long time for as far as we know, the stock filter.

try changing the filter first. there are 4 filters. one with 3 connections and one with 4. You will need to climb under the passenger side of the car in front of the rear tire and remove the plastic cover that covers the fuel pump. look at the fuel pump and either order the new one form JHMotorsports.com or you can get one at the dealer. chances are, you have the one with 3 connections on it.

if the sound does not go away after you change the filter then you need to replace the pump because chances are it was work out prematurely by the extra pressure it had to pump through with the dirty fuel filter.

you can get the fuel pump from JHMotorsports.com or the dealer. you will pay out of the ass if it is done by the dealer.

**JimmyBones** · 10-13-2010 08:11 PM

The main fuel pump does make a little noise priming the system normally when you turn the ignition on but most people do not notice. If you stick your ear to the right of the rear seat bench and have someone turn the ignition on then you will be able to hear the pump more clearly.

I would start with the fuel filter and these cars should use the three connection filter since the fuel filter has the fuel return valve inside. Of course the dealership can double check that with a VIN number. If the car will not start a few seconds after you changed the fuel filter then the lines are probably swapped and the fuel pump is dumping the pressure back into the tank.

The filter is cheap and hope that is it because a fuel pump is around $400 to $500 for the part which doesn't include labor!

**BCsniper** · 10-13-2010 08:50 PM

I'm guessing mine's in the same situation since I've been hearing pretty much the same thing. A fuel filter was on my list of things to do already....along with like 20 other things I want to get to eventually. I guess now I should move it to more priority status, since it looks as if replacing the pump isn't a job I want to have to do.

**dannslc** · 10-13-2010 09:24 PM

Me too. I've def been hearing the loud prime noise off and on for about a month. Where's the best place to order new filters from?

**dannslc** · 10-13-2010 09:29 PM

ecs has four different choices. which one does everybody usually go with?

**whartung** · 10-13-2010 09:30 PM

JHM.

And instead of taking the cover off you can just reach your hand in between the cover and count how many outlets your fuel filter has. Mine was clogged enough to cause problems at 59k miles.

**dannslc** · 10-13-2010 09:33 PM

Wow ok. Mines gotta be done for sure. I will order one tomorroe. thanks.

**Rennspeed** · 10-21-2010 09:14 PM

JDAutosports.com (A Shop in Portland Oregon specializing in the B5 2.7. and B6/B7 4.2L Audi S4) replaced my (4 connection, not 3) Fuel Filter this afternoon. The priming noise is GONE.

All of the information and advice was greatly appreciated.

Thank you again!

B6 S4: Arctic White, VMR 710 Wheels, KW Coilovers, H Sport Sways, RS4 Clutch, JHM Lightweight Single Mass Flywheel, JHM 4:1 Torsen Diff, JHM Snub Mount, Unitronic Stage 2+ Software, Miltek Full Exhaust, JHM Intake Spacers, Stratmosphere Hyperflow Intake, Navigation, HID Fog Lamps

**Rennspeed** · 10-21-2010 09:45 PM

Another forum member posted a video that recorded the EXACT noise I was attempting to describe.

Here it is :http://www.youtube.com/watch?v=0YEf_2PZ0Zk

Hopefully this will help anyone else out there trying to diagnose this symptom.

B6 S4: Arctic White, VMR 710 Wheels, KW Coilovers, H Sport Sways, RS4 Clutch, JHM Lightweight Single Mass Flywheel, JHM 4:1 Torsen Diff, JHM Snub Mount, Unitronic Stage 2+ Software, Miltek Full Exhaust, JHM Intake Spacers, Stratmosphere Hyperflow Intake, Navigation, HID Fog Lamps