Hi There

I have various Audi's with different problems and this one is a frustrating as the others. I bought the car recently with a known misfire on cylinder 2 so i replaced the coil packs and spark plugs as it was due a full service anyway and it seemed to be an electrical misfire. This has not cured the problem. The engine will initially start ok from cold and run fine but then starts to run lumpy and throw a fault code which shows as "cylinder 2 misfire" on a code reader. I then suspected a faulty injector which i have replaced with a new Bosch unit but it's still running exactly the same. I've done a compression test which seems to show all is fine although cylinder 2 was slightly lower than the others but not drastically. I then suspected carbon build up but when i changed the injector i inspected the intake valves and although they did have some carbon deposits it was quite even across all four cylinders and didn't seem that bad. I would have thought that if this was the problem then it would be evident from start up. Cylinder 2 spark plug does seem to show more sooty deposits than the others but not excessively. I'm assuming that cylinder 2 is the 2nd cylinder from the front of the car? If not then perhaps one of the other injectors is at fault 🤔 

 

You could get a compression test. 

HI Steve

I did a compression test myself and tried to do it when the engine was warm and i got 170psi on 1,3 &4 cyliders and about 150psi on cyl2. I would have expected a lot lower reading if the fault was carbon build up but i'm not that familiar with these engines so perhaps someone would have a better idea than me?

COILPACK BUD   

Already changed with plugs as well, still the same!