2002 320i has misfire and losing a cylinder intermittently , could be driving along normally and it would do it, if i turn the engine off and restart it , its back to normal, according to my diagnostic device which is a dedicated BMW one it's misfire in number 3 cylinder when it occurs, it's been in the garage and they replaced the spark plugs which i knew wouldn't be the cause and gave it back to me, of course it started again so took it back, they couldn't replicate the issue so they replaced the coil; with a demo one to try it out but the problem is back after a few hours, it has me stumped and hoping one of you BMW experts may be able to help or suggest something, any help would be greatly appreciated
