One of the spark plug bolts are completely rounded and the coil pack isnt sitting on it right. the previous owner must have tried and failed as the other 3 plugs look much newer. The car is juddering quite badly while accelerating I've plugged a diagnostics machine in and it's coming back clear. the majority of people I've told this to have been gobsmacked that some idiot actually rounded off a spark plug. it's my first car and I just want it to drive smoothly. any and all suggestions would be greatly appreciated.
