Intermittent misfire on 2 cylinder 1998 S500
 

Car was showing 3 codes for multiple random misfire and misfire on 2 cylinders. Coils and plugs were replaced on the two effected cylinders by the dealer. Misfire remains, but is intermittent. The car will run perfect for hours and suddenly start missing consistently on those two cylinders. Compression test came back perfect as well.

Any ideas? I don't think a vacuum leak would effect just those two cylinders.

How many times have you pulled the codes after the misfire? And is it always the same two cylinders?

Which two cylinders?

wonder if anti sieze was used on plugs.Sometimes to much will cause missfires.I have heard to the V8s can have problem with a wire,rubbing on the block,causing shorts.

Can you pull fuel trim while it is running and while it is misfiring? Check out the timing? That would rule out anything fuel related and isolate to spark issues.


Sent from an abacus

Does this car have the ecojunk wiring harness?