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