Mister D

I have a 1.8T A6 Avant 1998. AEB engine, manual 5-speed, no mods. (this is a
UK/Euro spec. car but should be similar to A4 models in US)

Bought the car with Audi warranty, but that's run out. They fixed a few
problems for me but two remain unsolved, they kept giving me the 'your car
is fine, Sir' line and I was too busy at the time to muscle my way to some
proper service. Basically I was let down, and couldn't complain well enough!

Problem 1:

I have established that the front 'torque-stop' mount is bad. If I open the
bonnet (hood) and drive along (in an empty car park!) the engine bobs up and
down alarmingly. My gearstick moves back and forth on throttle inputs. This
is quite a common failure, I now gather, but at the time of warranty Audi
denied it was a problem, and I hadn't seen the engine movement. "They all do
that, Sir".

Looking on some tech. sheets (ETKA, Bentley, erWin) I see that the mount is
sited on the front cross-member, with a shaft that points back toward the
engine. Bolted to the front of the engine there is a cylindrical casting.
The rubber stop is in-between. (this may differ from A4's - where the female
end is on the cross-member ??) Anyone got an easy way to fix this? Don't
really want to drop the whole front off the car, but don't have a specific
tech. sheet that covers!

I now find that the cross-member is actually a tube for the charge-air from
the turbo to the intercooler. Is this right? If so, is it possible that the
constant movement from the mount may crack the metal, causing charge-air
leaks? I keep telling myself that VW would design out such a weak spot - but
can't help thinking this may be a factor in my other problem.

Problem 2:

Sometimes get a misfire from cold for about 20-30 secs. Anyhow, the car
simply lacks power up to 4000rpm, then seems to pull fine. Under load, there
is definite hesitation here and there but it's difficult to feel because of
problem 1! I have disconnected the N75 valve and felt the 'non turbo'
difference, so it's not a specific boost loss caused by electronic
safeguard. I have a VAG-COM and the car is throwing no fault codes! I have
checked and tightened the knock-sensors and they seem to work fine.

I've seen many posts describing the nice turbo noise these engines produce.
Mine is not so nice. It seems to be 'interrupted' and the rate of stutter
seems to correspond with the hesitation I feel. There is no 'warble' or
'honk', indeed, one of the things Audi DID do was to replace the BPV.

I've been trawling for info on these problems for a while now, would really
appreciate some pointers. Any website or book I could read? I'm not the
worlds best mechanic, but my current situation predicts that I must now
service this car myself, on a bit of a 'shoestring' budget! I'm just
building myself a new garage and extending the house, so when that's done
it'll be time to give my beloved vehicle some TLC. Gonna have a go anyway.
I've had this car for three years now and I really want to enjoy full
performance again.

Thanks for listening. Anyone who recognises these symptoms, or can help in
any way, please get in touch!

JP Roberts

Since you state you've had this car for 3 years, how come you're only just
realizing about all of this probs only now?

Anyway, if I were you I'd do the following and in the following order,
checking after every step, if you don't want to spend any unnecessary money:

1.- Run a Throttle Body Adaptation. You wouldn't believe what the difference
may be after running this successfully.

2.- Tank only 98 Octane petrol and over - just to make sure your usual booze
is not the culprit to a certain extent.

2b.- Check all the piping for leaks.

3.- Have your N75 valve replaced by an N75J. Surges might very well be
caused by a faulty N75

4.- Have the MAF cleaned or better still replaced.

And if you want to hear the nice turbo noise and feel the torque this engine
is naturally capable of, and have its consumption reduced, have it chipped
by a reliable installer.

My car - a '98 1.8TQ A4 had a defective TB and ditto N75. These and now the
two front wheel bearings are the only serious problems I've had with it for
six years. Now the car is so much better it no longer feels the same. If
only I'd found out sooner!

My two cents,

JP Roberts

"Mister D" <mister_d_nospam@hotmail.com> escribió en el mensaje
news:QIugc.67$T55.4@news-binary.blueyonder.co.uk...
> I have a 1.8T A6 Avant 1998. AEB engine, manual 5-speed, no mods. (this is
a
> UK/Euro spec. car but should be similar to A4 models in US)
>
> Bought the car with Audi warranty, but that's run out. They fixed a few
> problems for me but two remain unsolved, they kept giving me the 'your car
> is fine, Sir' line and I was too busy at the time to muscle my way to some
> proper service. Basically I was let down, and couldn't complain well
enough!
>
> Problem 1:
>
> I have established that the front 'torque-stop' mount is bad. If I open
the
> bonnet (hood) and drive along (in an empty car park!) the engine bobs up
and
> down alarmingly. My gearstick moves back and forth on throttle inputs.
This
> is quite a common failure, I now gather, but at the time of warranty Audi
> denied it was a problem, and I hadn't seen the engine movement. "They all
do
> that, Sir".
>
> Looking on some tech. sheets (ETKA, Bentley, erWin) I see that the mount
is
> sited on the front cross-member, with a shaft that points back toward the
> engine. Bolted to the front of the engine there is a cylindrical casting.
> The rubber stop is in-between. (this may differ from A4's - where the
female
> end is on the cross-member ??) Anyone got an easy way to fix this? Don't
> really want to drop the whole front off the car, but don't have a specific
> tech. sheet that covers!
>
> I now find that the cross-member is actually a tube for the charge-air
from
> the turbo to the intercooler. Is this right? If so, is it possible that
the
> constant movement from the mount may crack the metal, causing charge-air
> leaks? I keep telling myself that VW would design out such a weak spot -
but
> can't help thinking this may be a factor in my other problem.
>
> Problem 2:
>
> Sometimes get a misfire from cold for about 20-30 secs. Anyhow, the car
> simply lacks power up to 4000rpm, then seems to pull fine. Under load,
there
> is definite hesitation here and there but it's difficult to feel because
of
> problem 1! I have disconnected the N75 valve and felt the 'non turbo'
> difference, so it's not a specific boost loss caused by electronic
> safeguard. I have a VAG-COM and the car is throwing no fault codes! I have
> checked and tightened the knock-sensors and they seem to work fine.
>
> I've seen many posts describing the nice turbo noise these engines
produce.
> Mine is not so nice. It seems to be 'interrupted' and the rate of stutter
> seems to correspond with the hesitation I feel. There is no 'warble' or
> 'honk', indeed, one of the things Audi DID do was to replace the BPV.
>
> I've been trawling for info on these problems for a while now, would
really
> appreciate some pointers. Any website or book I could read? I'm not the
> worlds best mechanic, but my current situation predicts that I must now
> service this car myself, on a bit of a 'shoestring' budget! I'm just
> building myself a new garage and extending the house, so when that's done
> it'll be time to give my beloved vehicle some TLC. Gonna have a go anyway.
> I've had this car for three years now and I really want to enjoy full
> performance again.
>
> Thanks for listening. Anyone who recognises these symptoms, or can help in
> any way, please get in touch!
>
>

Alec

Before you run a TB Adaption, check for carbon around the butterfly.
Rgds
Alec
"JP Roberts" <1234@yahoo.com> wrote in message
news:c5uqp1$i5f$1@news.ya.com...
> Since you state you've had this car for 3 years, how come you're only just
> realizing about all of this probs only now?
>
> Anyway, if I were you I'd do the following and in the following order,
> checking after every step, if you don't want to spend any unnecessary
money:
>
> 1.- Run a Throttle Body Adaptation. You wouldn't believe what the
difference
> may be after running this successfully.
>
> 2.- Tank only 98 Octane petrol and over - just to make sure your usual
booze
> is not the culprit to a certain extent.
>
> 2b.- Check all the piping for leaks.
>
> 3.- Have your N75 valve replaced by an N75J. Surges might very well be
> caused by a faulty N75
>
> 4.- Have the MAF cleaned or better still replaced.
>
> And if you want to hear the nice turbo noise and feel the torque this
engine
> is naturally capable of, and have its consumption reduced, have it chipped
> by a reliable installer.
>
> My car - a '98 1.8TQ A4 had a defective TB and ditto N75. These and now
the
> two front wheel bearings are the only serious problems I've had with it
for
> six years. Now the car is so much better it no longer feels the same. If
> only I'd found out sooner!
>
> My two cents,
>
> JP Roberts
>
> "Mister D" <mister_d_nospam@hotmail.com> escribió en el mensaje
> news:QIugc.67$T55.4@news-binary.blueyonder.co.uk...
> > I have a 1.8T A6 Avant 1998. AEB engine, manual 5-speed, no mods. (this
is
> a
> > UK/Euro spec. car but should be similar to A4 models in US)
> >
> > Bought the car with Audi warranty, but that's run out. They fixed a few
> > problems for me but two remain unsolved, they kept giving me the 'your
car
> > is fine, Sir' line and I was too busy at the time to muscle my way to
some
> > proper service. Basically I was let down, and couldn't complain well
> enough!
> >
> > Problem 1:
> >
> > I have established that the front 'torque-stop' mount is bad. If I open
> the
> > bonnet (hood) and drive along (in an empty car park!) the engine bobs up
> and
> > down alarmingly. My gearstick moves back and forth on throttle inputs.
> This
> > is quite a common failure, I now gather, but at the time of warranty
Audi
> > denied it was a problem, and I hadn't seen the engine movement. "They
all
> do
> > that, Sir".
> >
> > Looking on some tech. sheets (ETKA, Bentley, erWin) I see that the mount
> is
> > sited on the front cross-member, with a shaft that points back toward
the
> > engine. Bolted to the front of the engine there is a cylindrical
casting.
> > The rubber stop is in-between. (this may differ from A4's - where the
> female
> > end is on the cross-member ??) Anyone got an easy way to fix this? Don't
> > really want to drop the whole front off the car, but don't have a
specific
> > tech. sheet that covers!
> >
> > I now find that the cross-member is actually a tube for the charge-air
> from
> > the turbo to the intercooler. Is this right? If so, is it possible that
> the
> > constant movement from the mount may crack the metal, causing charge-air
> > leaks? I keep telling myself that VW would design out such a weak spot -
> but
> > can't help thinking this may be a factor in my other problem.
> >
> > Problem 2:
> >
> > Sometimes get a misfire from cold for about 20-30 secs. Anyhow, the car
> > simply lacks power up to 4000rpm, then seems to pull fine. Under load,
> there
> > is definite hesitation here and there but it's difficult to feel because
> of
> > problem 1! I have disconnected the N75 valve and felt the 'non turbo'
> > difference, so it's not a specific boost loss caused by electronic
> > safeguard. I have a VAG-COM and the car is throwing no fault codes! I
have
> > checked and tightened the knock-sensors and they seem to work fine.
> >
> > I've seen many posts describing the nice turbo noise these engines
> produce.
> > Mine is not so nice. It seems to be 'interrupted' and the rate of
stutter
> > seems to correspond with the hesitation I feel. There is no 'warble' or
> > 'honk', indeed, one of the things Audi DID do was to replace the BPV.
> >
> > I've been trawling for info on these problems for a while now, would
> really
> > appreciate some pointers. Any website or book I could read? I'm not the
> > worlds best mechanic, but my current situation predicts that I must now
> > service this car myself, on a bit of a 'shoestring' budget! I'm just
> > building myself a new garage and extending the house, so when that's
done
> > it'll be time to give my beloved vehicle some TLC. Gonna have a go
anyway.
> > I've had this car for three years now and I really want to enjoy full
> > performance again.
> >
> > Thanks for listening. Anyone who recognises these symptoms, or can help
in
> > any way, please get in touch!
> >
> >
>
>

Hairy One Kenobi

"Mister D" <mister_d_nospam@hotmail.com> wrote in message
news:QIugc.67$T55.4@news-binary.blueyonder.co.uk...
> I have a 1.8T A6 Avant 1998. AEB engine, manual 5-speed, no mods. (this is
a
> UK/Euro spec. car but should be similar to A4 models in US)

> I have established that the front 'torque-stop' mount is bad. If I open
the
> bonnet (hood) and drive along (in an empty car park!) the engine bobs up
and
> down alarmingly. My gearstick moves back and forth on throttle inputs.
This
> is quite a common failure, I now gather, but at the time of warranty Audi
> denied it was a problem, and I hadn't seen the engine movement. "They all
do
> that, Sir".

Common on Minis, maybe (although that was the gearstick bobbin - same
effect).

Basically, I'd say that you've thrown an engine mount of some description
(if the "torque stop" is just a bit of rubber to stop the negine doing
metal-on-metal - which I'm assuming is the case - then take a look at the
other mounts. Easy enough to do - just *slowly* jack up the engine and see
which part is no longer connected to the chassis..)

> Problem 2:

> I've seen many posts describing the nice turbo noise these engines
produce.
> Mine is not so nice. It seems to be 'interrupted' and the rate of stutter
> seems to correspond with the hesitation I feel. There is no 'warble' or
> 'honk', indeed, one of the things Audi DID do was to replace the BPV.

I'm guessing that "BPV" = "By Pass Valve", or "Diverter Valve/DV" to any
Audi type. Someone can probably help you with the exact working version
(J/K/H/whatever) - I gave up and fitted an aftermarket unit from Forge.
Utterly reliable, only took a few minutes to change. The worst part was
getting at the hose clips..

The "goose honk" is a classic symptom (although, in may case, it showed as
being gutless, rather than noisy)

The design may vary on the A6, but the aluminium tube is indeed to pass air
(on the TT, at any rate)

> I've been trawling for info on these problems for a while now, would
really
> appreciate some pointers. Any website or book I could read? I'm not the
> worlds best mechanic, but my current situation predicts that I must now
> service this car myself, on a bit of a 'shoestring' budget!

Without trying to appear rude, I suggest that you ask around locally, to see
if there is a local mechanic with a decent labour rate - if you know where
to go, you can often find that they charge 1/3 as much as a dealer. All well
and good trying to learn, but (in my case, when I was starting out) Mini
parts are a *lot* cheaper than Audi! ;o)

HTH

Hairy One Kenobi

Disclaimer: the opinions expressed in this opinion do not necessarily
reflect the opinions of the highly-opinionated person expressing the opinion
in the first place. So there!

Steve

A big thanks for the replies to this thread - unfortunately my isp won't
keep many messages on its server so I found them on Google and am replying
here.

Hairy One: I'm not just starting out, sorry should have said! I used to have
classic cars in my youth (I'm 37 now) and have worked on many a Triumph. I
agree about the parts!
Alec: What would carbon around the butterfly indicate? Rich mixture?
J.P: Yes I have had the car for 3 years, spent the first (warranty) year
trying to get Audi to fix everything that was wrong. Since then I've been
working on renovating my house, so the Audi has been waiting in the wings.
I've been rebuilding the garage as part of an extension to the house. I've
lived with having to drive this sloppy drivetrain around for long enough!

I could live with the problems if I hadn't had an A6 previously. I remember
that car and how it drove. It was a joy. (It was also my wife's company car)
I decided to get my own, with the intention of some light modding - maybe a
chip - and just to enjoy it for the space and comfort, holidays and the
like.

So now I'm nearing the time where I can finally put the thing in order. I
just need as much information as I can gather, to give me the fullest
picture of what can be done to get this car into tip-top driving shape. I
bought a great book, 'Bosch Fuel Injection & Engine Management', from
Bentleys and it's given me a great insight into what makes these newer cars
tick. Trouble is there is nothing specific to my car, as the book was
written a few years back. Still, it's taken all the 'mystery' away from the
engine management side. A good read.

I have a VAG-COM, as I think I mentioned, and also some good manuals, so I'm
not scared to roll up those sleeves now! I just would like some more 'horses
mouth' type info.

I will, of course, try to keep you guys updated on my progress. Is there a
better discussion group to do this?

Thanks again,
Steve

Hairy One Kenobi

"Steve" <s-d-s@NO.THANKS.blueyonder.co.uk> wrote in message
news:0avhc.1247$hH3.347@nurse.blueyonder.net...
> A big thanks for the replies to this thread - unfortunately my isp won't
> keep many messages on its server so I found them on Google and am replying
> here.

<snip>

> I will, of course, try to keep you guys updated on my progress. Is there a
> better discussion group to do this?

Here, plus any model-specific forums (e.g. you can read about the TT DV
"goose honk" by searching the old TT Forum from 2000.

H1K