Rough idle when cold. Errors when pulling trailer.

[Flyingdutchman]

BMW E53 N62 2005

Hi

More mysterious errors with my Betty. Thought I'll see if it ring a bell to someone:

1. Rough idle when cold. Hear a click sound in engine bay causing dip in engine rpm. Not AC.

No error codes set during this part. Not sure the following is related but been pulling a trailer lately:

2. Engine light blinking when pulling trailer uphill and downhill.
3. Twice engine light stayed on and whole car was shaking. Had to stop and restart the engine and all was fine again.

Kind of interesting because second part of the trip was more flat and the error didn't come back so seemed related to the hilly parts.

Errors in system, P0300 Multiple misfire, P0308 Misfire cil 8, P0307 misfire cil 7 and P0305 Misfire cil 5.