I've had my 2003 Audi A4 1.9TDi for nearly a year and been very pleased
with it however on 3 occasions I've noticed odd behaviour. After approx
half an hour of enthusiastic driving on A roads (i.e lots slowing for
junctionas etc and then rapid acceleration) I seem to loose most of the
power, acceleration is VERY sluggish. There are no warning lights or
other symptoms. If I stop and re-start the car immediately the problem
is gone. It's only happened on three occasions some months apart with
plenty of similar driving in between

Any ideas as to the cause?

Mike

 

"Mike" <mikeloveschampagneandrugby@googlemail.com> wrote in message
news:g0f9k1$uoc$1@registered.motzarella.org...
> I've had my 2003 Audi A4 1.9TDi for nearly a year and been very pleased
> with it however on 3 occasions I've noticed odd behaviour. After approx
> half an hour of enthusiastic driving on A roads (i.e lots slowing for
> junctionas etc and then rapid acceleration) I seem to loose most of the
> power, acceleration is VERY sluggish. There are no warning lights or
> other symptoms. If I stop and re-start the car immediately the problem is
> gone. It's only happened on three occasions some months apart with plenty
> of similar driving in between
>
> Any ideas as to the cause?
>
> Mike

auto or manual.

 

Mike wrote:
> I've had my 2003 Audi A4 1.9TDi for nearly a year and been very pleased
> with it however on 3 occasions I've noticed odd behaviour. After approx
> half an hour of enthusiastic driving on A roads (i.e lots slowing for
> junctionas etc and then rapid acceleration) I seem to loose most of the
> power, acceleration is VERY sluggish. There are no warning lights or
> other symptoms. If I stop and re-start the car immediately the problem
> is gone. It's only happened on three occasions some months apart with
> plenty of similar driving in between
>
> Any ideas as to the cause?
>
> Mike
Get the codes read with VAG-COM or a dealer computer.

It sounds like a sticking VNT mechanism on the turbo. It will probably
leave a code 'overboost detected' or similar. The vanes stick, the turbo
overboosts, so then the ECU shuts down the turbo. That's why turning it
off clears it. This almost always happens after or during hard
accelleration.

The official fix is a new turbo, though you may get an improvement by
working the VNT mechanism back and forth a bit by hand.

http://forums.tdiclub.com/showthread.php?t=140910 may also help you out,
and
http://www.technologie-entwicklung.d...t15-turbo.html

shows the VNT mechanism in action.

 

tpow wrote:
> "Mike" <mikeloveschampagneandrugby@googlemail.com> wrote in message
> news:g0f9k1$uoc$1@registered.motzarella.org...
>> I've had my 2003 Audi A4 1.9TDi for nearly a year and been very pleased
>> with it however on 3 occasions I've noticed odd behaviour. After approx
>> half an hour of enthusiastic driving on A roads (i.e lots slowing for
>> junctionas etc and then rapid acceleration) I seem to loose most of the
>> power, acceleration is VERY sluggish. There are no warning lights or
>> other symptoms. If I stop and re-start the car immediately the problem is
>> gone. It's only happened on three occasions some months apart with plenty
>> of similar driving in between
>>
>> Any ideas as to the cause?
>>
>> Mike
>
> auto or manual.
>

Manual

Mike

 

Chris Bartram wrote:
> Mike wrote:
>> I've had my 2003 Audi A4 1.9TDi for nearly a year and been very
>> pleased with it however on 3 occasions I've noticed odd behaviour.
>> After approx half an hour of enthusiastic driving on A roads (i.e
>> lots slowing for junctionas etc and then rapid acceleration) I seem
>> to loose most of the power, acceleration is VERY sluggish. There are
>> no warning lights or other symptoms. If I stop and re-start the car
>> immediately the problem is gone. It's only happened on three
>> occasions some months apart with plenty of similar driving in between
>>
>> Any ideas as to the cause?
>>
>> Mike
> Get the codes read with VAG-COM or a dealer computer.
>
> It sounds like a sticking VNT mechanism on the turbo. It will probably
> leave a code 'overboost detected' or similar. The vanes stick, the turbo
> overboosts, so then the ECU shuts down the turbo. That's why turning it
> off clears it. This almost always happens after or during hard
> accelleration.
>
> The official fix is a new turbo, though you may get an improvement by
> working the VNT mechanism back and forth a bit by hand.
>
> http://forums.tdiclub.com/showthread.php?t=140910 may also help you out,
> and
> http://www.technologie-entwicklung.d...t15-turbo.html
>
>
> shows the VNT mechanism in action.

Thought it might be turbo related, fortunately I have a warranty so I
won't be getting my hands dirty!

Mike

 

"Mike" <mikeloveschampagneandrugby@googlemail.com> wrote in message
news:g0hqqm$2b1$1@registered.motzarella.org...
> tpow wrote:
>> "Mike" <mikeloveschampagneandrugby@googlemail.com> wrote in message
>> news:g0f9k1$uoc$1@registered.motzarella.org...
>>> I've had my 2003 Audi A4 1.9TDi for nearly a year and been very pleased
>>> with it however on 3 occasions I've noticed odd behaviour. After approx
>>> half an hour of enthusiastic driving on A roads (i.e lots slowing for
>>> junctionas etc and then rapid acceleration) I seem to loose most of the
>>> power, acceleration is VERY sluggish. There are no warning lights or
>>> other symptoms. If I stop and re-start the car immediately the problem
>>> is gone. It's only happened on three occasions some months apart with
>>> plenty of similar driving in between
>>>
>>> Any ideas as to the cause?
>>>
>>> Mike
>>
>> auto or manual.
>
> Manual
>
> Mike

OK it was just that the auto's have a remember function (mine seems to)
whereby they get used to driving techniques. I travel the same roads every
day for 5 days per week, if I take a detour along a certain road that has a
fairly steep hill, when I reach the top the box stays in 3rd or 4th for a
while over the top. No matter what I try it will only change when it wants
to.

yes yours is probably turbo related.