Could the OP be hearing the fuel pump?
I am thinking that his current fuel filter is partially clogged making
the fuel pump work harder and become noisier.
Maybe a fuel filter change might allow more fuel to travel through the
system.
When was the last time that you changed the filter?

Others have suggested bearings and tires so I threw out another idea.

Exhaust vibration?

My $0.02
later,
dave
(One out of many daves)

 

Could the OP be hearing the fuel pump?
I am thinking that his current fuel filter is partially clogged making
the fuel pump work harder and become noisier.
Maybe a fuel filter change might allow more fuel to travel through the
system.
When was the last time that you changed the filter?

Others have suggested bearings and tires so I threw out another idea.

Exhaust vibration?

My $0.02
later,
dave
(One out of many daves)

 

Could the OP be hearing the fuel pump?
I am thinking that his current fuel filter is partially clogged making
the fuel pump work harder and become noisier.
Maybe a fuel filter change might allow more fuel to travel through the
system.
When was the last time that you changed the filter?

Others have suggested bearings and tires so I threw out another idea.

Exhaust vibration?

My $0.02
later,
dave
(One out of many daves)

 

"Grapeape" <grape@ape.com> wrote in message
news:45289b51$0$14716$c3e8da3@news.astraweb.com...
>I have a 2000 Audi A4 2.8 Quattro. Recently it has developed a constant
> noise, and I am wondering what it might be. Here are the details:
>
> * The noise gradually appeared over the last month or two. It started
> as: "Is the car a little louder than usual?" and now is: "The car is a
> lot louder than usual."
> * The noise could be characterized as a roar; it is almost like road
> noise
> * It is not at all cyclical. It is a constant drone or roar that
> remains the same as long as I'm going a particular speed
> * It seems to come from the rear half of the vehicle
> * It does not increase with acceleration, like a muffler problem. In
> fact, it is most noticeable when cruising along at a constant speed in
> a low to middle gear, or when the wheels are turning but I am not
> pressing on the gas
>
> I am not experienced with cars, so an obvious problem can't be ruled
> out.
>
> Any thoughts?
>
> Thanks in advance!
>
>
> --------------= Posted using GrabIt =----------------
> ------= Binary Usenet downloading made easy =---------
> -= Get GrabIt for free from http://www.shemes.com/ =-
L
Like others have said........

Bearings, they are sealed and will just get louder and louder untill you can
no longer bear the sound
>

 

"Grapeape" <grape@ape.com> wrote in message
news:45289b51$0$14716$c3e8da3@news.astraweb.com...
>I have a 2000 Audi A4 2.8 Quattro. Recently it has developed a constant
> noise, and I am wondering what it might be. Here are the details:
>
> * The noise gradually appeared over the last month or two. It started
> as: "Is the car a little louder than usual?" and now is: "The car is a
> lot louder than usual."
> * The noise could be characterized as a roar; it is almost like road
> noise
> * It is not at all cyclical. It is a constant drone or roar that
> remains the same as long as I'm going a particular speed
> * It seems to come from the rear half of the vehicle
> * It does not increase with acceleration, like a muffler problem. In
> fact, it is most noticeable when cruising along at a constant speed in
> a low to middle gear, or when the wheels are turning but I am not
> pressing on the gas
>
> I am not experienced with cars, so an obvious problem can't be ruled
> out.
>
> Any thoughts?
>
> Thanks in advance!
>
>
> --------------= Posted using GrabIt =----------------
> ------= Binary Usenet downloading made easy =---------
> -= Get GrabIt for free from http://www.shemes.com/ =-
L
Like others have said........

Bearings, they are sealed and will just get louder and louder untill you can
no longer bear the sound
>

 

"Grapeape" <grape@ape.com> wrote in message
news:45289b51$0$14716$c3e8da3@news.astraweb.com...
>I have a 2000 Audi A4 2.8 Quattro. Recently it has developed a constant
> noise, and I am wondering what it might be. Here are the details:
>
> * The noise gradually appeared over the last month or two. It started
> as: "Is the car a little louder than usual?" and now is: "The car is a
> lot louder than usual."
> * The noise could be characterized as a roar; it is almost like road
> noise
> * It is not at all cyclical. It is a constant drone or roar that
> remains the same as long as I'm going a particular speed
> * It seems to come from the rear half of the vehicle
> * It does not increase with acceleration, like a muffler problem. In
> fact, it is most noticeable when cruising along at a constant speed in
> a low to middle gear, or when the wheels are turning but I am not
> pressing on the gas
>
> I am not experienced with cars, so an obvious problem can't be ruled
> out.
>
> Any thoughts?
>
> Thanks in advance!
>
>
> --------------= Posted using GrabIt =----------------
> ------= Binary Usenet downloading made easy =---------
> -= Get GrabIt for free from http://www.shemes.com/ =-
L
Like others have said........

Bearings, they are sealed and will just get louder and louder untill you can
no longer bear the sound
>