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Chris (aka - Moose)
Chris (aka - Moose), Technician
Category: Audi
Satisfied Customers: 48325
Experience:  16 years of experience
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Audi A8 Quattro L: I have a 2005 Audi A8L and this morning

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I have a 2005 Audi A8L and this morning I noticed a pulsating humming noise coming from near my left front tire. It makes the noise while parked and intermittently while moving. I have read about fuel pump issues when fuel is low - my range is at 60 miles.  Update:

Filled tank, same sound.


Any ideas?

Hello, I'm Chris. Thanks for visiting Just Answer.


Can you open the hood and try to pinpoint this noise. Some of the possible causes are the transmission pump, power steering pump, broken motor mount, faulty exhaust hanger. See if you can get your hand on the culprit or pinpoint it a little better for me. Not being able to hear it, makes me finding it near impossible.


Customer: replied 3 years ago.

Okay, opened the hood. The noise seems to be coming from under the plastic cover on the firewall side of the engine...right in the middle. When I put my hand on the cover, I could feel the vibration. I see some hoses going under the cover but I don't know which ones they are. If you need me to take a picture, I will.

Can you remove the cover and touch things to try and find the source, then take a picture close up and from away from the culprit?


Customer: replied 3 years ago.

Under the Cover

Customer: replied 3 years ago.

I sent the picture. I forgot to add: it's the circular plastic thing that seems to be making the noise...I hate to describe it this way but it's almost like a muted honking noise.

This part is called the vacuum unit, if this is the source of the noise then inside it is a broken baffle, which is creating your noise. A new vacuum unit is the part needed.


Chris (aka - Moose) and other Audi Specialists are ready to help you
Hello again Chris here.

It has been a few days, so I am just checking in with you to see if you still need help with the concern we worked on, and if not to say Thanks.

Also note we have about 80 categories from medical to boats to small engines to legal to whatever you can think of. If you have any other questions give us a shot with another question.

Thanks Chris