Breakdown

[steve2003rs6]

Been out all day in the car. Dropped my sister in law off.
Went to start the car and nothing.
Newish battery was doing its job turning the car over but wouldn’t start.
AA came out and was with us within 1/2 hour. Technician went under the car and hit the fuel pump with a hammer. Car immediately fired up and we drove home.

AA van followed us to ensure we got home. About a 20 min drive.
AA were amazing.

Does anyone have a fuel pump for sale. Or know where I can get one.
Thank you in advance.

[TOPMAN]

Hi Steve, well that’s a bit crap.

There are 2 fuel pumps on our cars. The in-tank fuel pump is a high volume, low pressure pump. Then there is the high pressure pump located next to the fuel filter externally on the side of the tank. I’m assuming he tapped the external pump, which is 4B0906089A.
That’s an expensive pump so I’d want to make sure that the electrical connectors are all OK before paying the asking price. LLLParts in the UK has original Audi pumps in stock at £686.80 +p&p. There are only a few after market pumps that fit, but Bosch and Walbro make pumps that can deliver. The originals were made by TI Automotive for Audi.
If you are having pump changed, now is a good time to do the filter too Hope this helps and fingers crossed it’s only a dodgy electrical connection.


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[Shoppinit]

Could be the crank position sensor and the hitting the fuel pump was just a coincidence. At those prices I’d to be sure.

[steve2003rs6]

Hi Craig. Many thanks for your much appreciated advice.
Yes mate I reckon he tapped the external pump with his hammer.

Good advice to check the connections b4 forking out for a new pump.
Great to know you can get new ones from LLL. When possible I like to use OE parts. Ouch price ain’t cheap at 0.8 of a single R/S unit.
I already have a new filter in my parts box.
It was replaced in April when the car was serviced.

Annoying breakdown. But the RS6 is still one of the most reliable cars I have ever owned. Possibly due to the amount of work I have had done to the car.

Will get onto this problem asap when the garage has ramp availability

[TOPMAN]

Ben, this was my first thought. Those crank position sensors often get gunked up.
Does the crank sensor leave any fault codes if it’s not reading correctly?


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[steve2003rs6]

Hi Ben. Many thanks. Will see if CPS can be checked at the same time.
Can this be tested with VCDS ?

[Shoppinit]

No fault codes with the crank position sensor, usually. Annoyingly. Same for fuel pump.

You can’t really test the crank position sensor. Maybe with an oscilloscope. I don’t think you can get a reading with the Vagcom, but I wouldn’t bet my life on it.

[steve2003rs6]

Cheers Ben.
At least I now have a plan of action
Thank you both for your recommendations

[steve2003rs6]

Any part number for the crank position sensor.

[111marc111]

I recently changed the crank position sensor on my car.

After driving 30mins gently home one day it suddenly cut out while stationary at a junction. Car would crank but not fire. I did however have a code in the ecu relating to crank sensor though, can't remember exactly what code. Another tell tale sign was the rev counter reading zero despite the engine turning over on the starter.

Parked the car and went back 2 hours later, car immediately started and I drove the last 5mins home.

Decided the right thing to do was change the crank sensor before using it again, despite the fault never reoccurring while doing several stop starts albeit only on my driveway. There is plenty of examples of the crank sensors failing when warm and causing hot start issues initially.

After changing the crabk sensor car has behaved ever since. Well till the turbo died. Nothing untoward or obvious noticed physically with the old sensor. I do still have it in a box and I'm sure it had a part number on it. I'll check tomorrow for you Steve.

[steve2003rs6]

Cheers for that Marc.
Having thought about it. I asked the technician about the fault and why he thought it was a faulty pump.
He had asked me to turn the ignition on without starting the car, while He was laid on the road with his head under the rear offside of the car.
He said he couldn’t hear the fuel pump running with the ignition switched on.
So he tapped the pump with a hammer and the car fired up first time.

So I reckon a faulty pump or bad connections.
Will check the connections first.
But I reckon it requires a new pump.

[Shoppinit]

I wish the RS6 had a fuel pressure sensor. It would make diagnosing fuel related issues so much easier.

[steve2003rs6]

Totally agree Ben. With the amount of sensors on the car one more wouldn’t have been a problem.
Looks like it will be a costly repair.

At least it will be peace of mind when the new pump is installed.

I will run a scan with VCDS today to see if there are any errors recorded. Just for my info really.

[steve2003rs6]

When I look at fuel pump described above I believe that is the internal pump 4B0906089A cost is £686 ish. I think the access for this pump is under the rear passenger seat.

Looking for the external pump I believe it’s on the outside of the fuel tank, at the front and on the RH side.
Trying to get a part number for this pump.
I reckon this is the pump that the AA technician tapped with a hammer.

From what I have read. The internal pump is a large volume pump with no pressure this feeds
The external pump which is the pressure pump.

[steve2003rs6]

My mistake.
Internal pump is 4B0906087BF I believe NLA
External pump is 4B0906089A as Topman advised £686 ish.