gragravar

what about when you are rolling but in neutral and not pressing accelerator?

Dr.quattro

I get a terrible humming from the front tires, thought it was bearings, cv joints, halfshafts, you name it.

Problem ended up being the tires.....Falken 451's.

blackIIIroad

I took my ar to the dealer 3 separate times and complained about this noise. It was even noted in my Audi vehicle records before I even bought the car. Complaint: Humming sound from rear! Every time dealer: couldn't reproduce sound. Then finally it pulled a code and they took the pump out to investigate. The pump was at one time fully flooded with water they said and the electrical system was on its way out! "We haven't seen anything like this." they added I guess one of the former owners decided to go four-wheeling through a river just to test the limits of this vehicle. Anywho after all this I ended up forking over $1000.00 buckaroos because this type water abuse wasn't covered by the 50K warranty. Easy fix the pump cost $899.95 so I just let them do it. Thanks previous 4wheelerperson

ar5154

I was just sitting in my car today wondering again what this noise might be. It is exactly as you describe. Comes on as you get on the gas and disappears at about 35 mph and then again when you come to a stop. Definitely something electrical, my guess is the fuel pump as mentioned. It seems to quiet down when there is no demand and has a "zone" where it is noisy.

allroadbryan

Have you taken yours to the dealer yet?

allroadbryan

into the rear tool kit compartment which is directly above the compressor and reservoir tank. The dealer still have not figured out the source of the leak. I will bring this up on my next visit. I'm also going to request that a mechanic or a service advisor take a ride with me to confirm the constant humming noise.

ar5154

Just had it in under my extended warranty for a rear pinion seal and forgot to have them look! If you can believe it I get used to it and forget about it. Please let me know if you find out anything from your visit.

skidmark

mostly anyhow, it's always pumping full flow. under boost it has to pump at a higher pressure because of fuel pressure regulator but is always flowing as much fuel as possible. excess fuel is just returned to tank.