2004 audi a4 1.8t.
Anyone have a howling or buzzing noise coming from under the car in the area of the rear passenger seat?
This noise don't fluctuate with the exhaust. There is a unit just under the plastic shroud in front of the rear wheel with a hose and another connection going to it this is the unit that seems to be making the noise.

Could this unit be related to emissions?
Any help would be great
Thanks Floyd

 

going off where your saying it is. if it sounds like a jet engine then its the smog pump and has a hole in the hose. do you have a check engine light? under what conditions does the noise happen? the smog pump for your new audi whould only run during the first five min of a cold start after that the noise would go away

 

The check engine light did come on for a few days then went out on its own. The noise starts from the time I start the engine right till I shut it off. The noise dosn't go away.

 

i mis read you initial post. i thought you were talking about the front of the car. your fuel pump is right there. it might be on its way out but you could always replace the fuel filter.

 

Remove the stray cat that got stuck there while looking for a warm place to take a nap, and the noise should go away.
Yup! definitely a cat. The hose you see is actually the tail...
Sorry, I could not resist!!!

 

Should I pull the hose (tail) and hope for the best. LOL

 

It is the fuel pump I had that problem to and had it replaced and the little buzzing noise went away.

 

I replaced the fuel filter and the noise went away.

 

Its been a while since any posted, hope you'll answer me!
i have the same "humming" noise, almost resembles a jet engine or city bus..
it was doing it for about a week then all of the sudden on my way to work i hear a god awful "CLICK CLACK" noise and the humming seemed to almost get quieter..

Do You think it could be a Wheel Bearing? The noise has always sounded like its under the car right under the rear seats.... just like someone stated in the above post..

I currently parked it in my garage and am not gonna drive it untill i can take it in to the shop. id just hate to spend $1000's for somthing i could do myself!!

PLEASE HELP!