Splutter/ miss/ backfire- arcing coil packs

cantdecide

I dropped my 98 A6 2.8 (V6, btw) with 130k on the clock to a garage and they did the rocker cover gaskets.

Immediately after picking it up, I noticed a miss in the engine. I thought it would clear because the car had been laid up for almost a fortnight. It got worse and worse quickly and after a day or two seems to be only firing on 4 cylinders and would backfire under load.

My first reaction was 'those ba*tards have messed something up'. But I decided I'd go back and thump the table and it would have just been a coincidence and I'd end up with egg on my face so I tried to figure it out myself.

The leads were only fitted in Sept/Oct 08 and AFAIK, the plugs had less than 10k on them. The coilpack is a complete unit, but split into 3 sets of 2. At night, I opened the bonnet and I could see arcing alongside one of the 3 units. Eureka, I thought and ordered the unit.

I fitted it but there was no improvement in the splutter. When I checked the new unit at night, I could see arcing alongside 2 pairs of the coilpack units.

Is it a faulty unit or is there something that could cause this to happen??

Neilw

Do the coil packs need to be earthed to the block, are all connections made properly, check the connection and wires for cracks.