Audi 2.5 tdi suddenly sounds like a plane

Hi there i have a 1997 audi 2.5 tdi with 75000 miles and just the other day
i was driving the car along the road and it sounds like there seems to be a
loud like fan stuck on and the more you rev it the louder it gets.I use to
have many 4x4 ford sierra,s 2.8 and i can recall fitting many viscus
coupling,s fans to them.This noise i have on my audi is the same as that
or a plane takin of which is noisy and then once it gets up in the sky it
the engines backs of to become quiet again well my audi sounds like its
keeps takin of or sounds like the choke is stuck on or could it be a
sensor.Can anyone please help me it would be much appreciated.

Regards,

John Mann.

> Hi there i have a 1997 audi 2.5 tdi with 75000 miles and just the other
day
> i was driving the car along the road and it sounds like there seems to be
a
> loud like fan stuck on and the more you rev it the louder it gets.I use to
> have many 4x4 ford sierra,s 2.8 and i can recall fitting many viscus
> coupling,s fans to them.This noise i have on my audi is the same as that
> or a plane takin of which is noisy and then once it gets up in the sky it
> the engines backs of to become quiet again well my audi sounds like its
> keeps takin of or sounds like the choke is stuck on or could it be a
> sensor.Can anyone please help me it would be much appreciated.

Is it the 5-cylinder one or the later V6 diesel? I've got the 5-cylinder
one, and the electric fan runs all the time as the aircon uses it (don't ask
me how or why!), and there is also a viscous fan there. Haven't had that
problem on mine - I guess it's just stuck on the fast setting - you'll
probably need to replace it if it's that annoying.

Peter
--
"The truth is working in television is not very glamorous at all. I just go
home on my own at night and sit alone and eat crisps."

The problem is not the fan or choke or ...

It is a sticking high speed fan relay. Probably in the main relay box on your model.

You need to replace it.


dellboy wrote:

> Hi there i have a 1997 audi 2.5 tdi with 75000 miles and just the other day
> i was driving the car along the road and it sounds like there seems to be a
> loud like fan stuck on and the more you rev it the louder it gets.I use to
> have many 4x4 ford sierra,s 2.8 and i can recall fitting many viscus
> coupling,s fans to them.This noise i have on my audi is the same as that
> or a plane takin of which is noisy and then once it gets up in the sky it
> the engines backs of to become quiet again well my audi sounds like its
> keeps takin of or sounds like the choke is stuck on or could it be a
> sensor.Can anyone please help me it would be much appreciated.
>
> Regards,
>
> John Mann.
>

"dellboy" > wrote in message
lkaboutautos.com...
> Hi there i have a 1997 audi 2.5 tdi with 75000 miles and just the other
> day
> i was driving the car along the road and it sounds like there seems to be
> a
> loud like fan stuck on and the more you rev it the louder it gets.I use to
> have many 4x4 ford sierra,s 2.8 and i can recall fitting many viscus
> coupling,s fans to them.This noise i have on my audi is the same as that
> or a plane takin of which is noisy and then once it gets up in the sky it
> the engines backs of to become quiet again well my audi sounds like its
> keeps takin of or sounds like the choke is stuck on or could it be a
> sensor.Can anyone please help me it would be much appreciated.
>
> Regards,
>
> John Mann.
>

It happened on VW engines. Oil found it's way from the oil pan vent into the
cylinders and kept sucked upward.
It makes noise like full trottle. Later they redesigned the vent.

Ronald

Are you sure it's not speed-dependant instead of rev? If so, and given your
mileage I'd bet it's wheel bearings!

JP Roberts


"dellboy" > escribió en el mensaje
lkaboutautos.com...
> Hi there i have a 1997 audi 2.5 tdi with 75000 miles and just the other
day
> i was driving the car along the road and it sounds like there seems to be
a
> loud like fan stuck on and the more you rev it the louder it gets.I use to
> have many 4x4 ford sierra,s 2.8 and i can recall fitting many viscus
> coupling,s fans to them.This noise i have on my audi is the same as that
> or a plane takin of which is noisy and then once it gets up in the sky it
> the engines backs of to become quiet again well my audi sounds like its
> keeps takin of or sounds like the choke is stuck on or could it be a
> sensor.Can anyone please help me it would be much appreciated.
>
> Regards,
>
> John Mann.
>