I noticed today that I'm getting a whining noise from the back of the car, no I know that's most likely the fuel pump but what I was wondering is if a rough idle would be a result of that also?

also my wife said she heard the whining noise get louder when I put it in park, that made me thing transmission, but when I rev the car the noise doesn't change.

are fuel pumps common on these cars?
I have 115000 km

 

Have your mechanic look at the fuel pressure individually at both pumps.
the driver's side is the first one to fail, but always replace them both at the same time.

 

Ok hold on a sec, there are two fuel pumps on these cars?
Do you think that would cause a rough idle?

 

Yes indeed.
poor/sluggish performance/erratic idle.
one fuel pump alone will get you to your destination but you will not have the full potencial of the engine.

 

also check on the passenger side pump housing for an o-ring fixture attached to it, when the ring leaks it makes humming noise.
and yes they do have 2 fuel pumps, nothing new dual pumps have been used since the mid 80s in big German sedans, we all know back then Audi was nowhere near that field.

 

wow thanks for the info, I had no idea these cars had 2 pumps, I assumed it was only on the direct injected models.

any idea how to check the pressure at the pumps?

 

if you don't have the right tools don't try it, you can have a huge fuel spill.
one easy way to see if they work is disconnecting one first while the engine is running and see if the engine change speed or dies, if no difference plug it back and unplug the second one, if it dies while doing this you have a dead pump.

 

great advise, I'll try that, so I guess if one is dying it wont really tell me much thought, only if its already dead right?

 

I've started to get a faultcode of "too lean idle fuel mixture" on BOTH bank 1&2 (so it's the passenger side of the engine) on my W12, suspecting a fuel pump, but no whining yet. 215000km on the clock.

The faultcode comes up ONLY after engine braking for a longer period of time at low rpm and high gear, ie. slowing down from 80km/h.

Had some trouble with the passenger side FRONT lambda connectors, created faultcodes on the lambda sensors 1&2 on "pumping", but was corrected with just inspecting the connectors. The fault there also came up while engine braking.

Wondering, are the two fuel rails connected together, or why would the failure of one pump affect just the idle the most?

No rough idle here... tough could a W12 have a rough idle...

And if you put mine on "tipronic" like 4-6gear and do a pull at low revs the engine "shakes" roughly. Does this sound like the fuel pump, i think it does?

Can you buy the pumps separately from audi, or just the whole tank system as usual that costs like 5000 euros (at minimum) here (already the floor mats are 350euros )

Or then i'll just replace the pumpus by a bosch replacement part. No need to replace my volvo S90 -98 fuel pump with 300000km on the clock...

I suspect it's the prolonged fuel filter change intervals on newer cars that clogs up the filter, and then destroys the pump, when the pump has to work harder to get gas trough the filter.

The S90 has an filter change interval of 60000km, while newer cars i've changed filters on have a 160000 interval. No need to repace pumps on ord RWD volvos before 300000km, but the newer cars need the pump&filter replaced @ 150-160000km (changed many).

 

FWIW: I was getting two faoult codes indicating too lean on banks 1 and 2 on my 4.2L V8. It turned out to be the air filter box (your W12 has two of them) was incorrectly reassembled by a dealer that I had do one oil change since they were replacing the coil packs for the recall anyway. I started to get erratic check engine lights with that fault. One screw was mis-aligned causing the air box to have a 1/2" air leak. Reassembled and all was well again.