Diagnosis please!

[nl328i]

Hi all,

I'm trying to diagnose an issue with my s50 swap.

It appears to have a misfire, but only once the car warms up and really only at wot. It seems to idle just fine and for the first few minutes runs fine at wot.

I'm thinking coils going bad. I might start there. Any other suggestions?

[JohnyEndo]

Def sounds like coils to me. Scan it and swap the misfiring cylinders coil to a good one(preferably not right next to the bad one) and rescan. If it follows the coil, there ya go. Other wise its the plug or you'll be doing a compression test. Although unlikely, plugs tend to miss more at idle and clear up under load. And a compression issue would be more permanent.