My car is a 2007 S3 with only 61000km on the clock. I have an irritating
problem that leaves me and the dealers completely puzzled. When accelerating
hard, usually above 4000 rpm, the car seems to produce a short misfire or that
is what it feels like. Usually only 1 or 2 misfires during the hard
acceleration but then the car continuous to accelerate freely to the red line.
No traction control light flashing, no engine warning lights displayed. The
funny thing is this doesn't happen every time. Sometimes I can drive hard for a
week with no misfire, but then all of a sudden the misfire is produced.
The car has been at the dealer 3 times already to find the problem, but still
the problem persists. They have done:
No error codes reported by VAS
Diverter valve replaced with the newer type valve
Thrust sensor replaced
O-rings on the boost pipe was apparently replaced
The high pressure fuel pump was checked for wear and seems to be in good
Fuel filter was replaced
Replaced clutch/pressure plate/release bearing
I use 95 RON fuel in the car, but sometimes use a quarter tank 93 RON when 95
is not available.
The maintenance plan is ending very soon and I would like to identify the
problem preferably before then.
Your help and advice will obviously be appreciated.