Pete 0 Report post Posted June 21, 2018 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 Quote Share this post Link to post Share on other sites
qube 3570 Report post Posted June 21, 2018 Can we safely rule out that it is not a coil pack issue? The demo one you tried could it be a dud? You can easily swap coil packs around each cylinder etc and see if the misfiring moves with the coil. 1 Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted June 21, 2018 ^^^^ This. Or it may not infact be a coil issue but instead a vacuum leak causing cyl 3 misfire 1 Quote Share this post Link to post Share on other sites
