This morning on my way to work my 2002 A4 1.8t (63k) started to
hesitate under acceleration (manual trans) and then the CEL came on
and started flashing about once a second. The power dropped and I
could hear the exhaust sort of pop a little, like it might be firing
only 3 cylinders (?). It started at about the point where the car
usually hits its operating temp, if that makes a difference. I use
Shell gas primarily and just had the timing belt replaced and the rear
seal replaced. I'm the second owner and I know the coil pack was
replaced somewhere in the 25k region. When I parked the car there was
a definite wet sort of cooking smell, not burning, coming from the
exhaust. Didnt smell like coolant. And I could definitely hear
something through the exhaust that sounded like a rhythmic muffled
clank. Right now she's parked in the paring lot and I am afraid to
drive it too much because I know from experience that these problems
can get more expensive the more you drive on them. I bought a new set
of coils when I got the car thinking that I'd need to replace them,
but I didnt since the service tech @ the dealer told me to wait until
it started running like crap... is this what he meant? How do I
determine if its the coils? Or a knock sensor? or an O2 sensor?
ANY advice would be greatly appreciated.
Thanks
Mike