While driving home from work it started to run rough like it was down a cylinder limped it home and called at my mates garage. I had a look on google and people had mentioned plugs or coil pack's so we changed them still missing so removed all the plugs and put a camera down the plug holes no1,2,4 we'e dry no3 was wet with oil no4 looked like the plug was arking onto the piston. so then we compression tested it no1,2,4 were ok and no3 had no compression. For the last 18 months it' been drinking oil. I hope this helps
