dief

Hello All,

I have been reading the various posts on misfiring. I have a 97' A41.8T w/100,000 miles on it. I have just had my first problem, a misfire upon starting one day. I pulled the codes w/VAG and it translate to random misfire/misfire on cyl #3. So, I pulled and replaced each plug, all of them looked fine until I got to cyl #2, there was charred deposits on the underside of the spark plug assembly and the housing that leads to the spark plug hole had a lot of carbon build up/soot. Also, the top threaded part on the plug in cyl#2 had cracked off maybe from the heat?? Anyway, my question is if the misfire is on cyl#3, why does #2 look so bad while the others look fine? Still a misfire, so I'm going to change coil packs to see if the misfire moves. I'm just curious if the VAG code just always spits out a misfire on cyl #3. Any help would be appreciated.

dingster

Coils gets pretty weak on high mileage cars.

Swap the coils from cylinder to cylinder to see if the misfire changes. If so then you one coil is too weak.

The power stage, aka ignition amblifier on top of the airbox can also cause this.

I think the cheapest solution is probably to gap your plugs down a bit.