Sparkplugs? Coils? Injectors? Help?

[6ixcommas]

Bone stock M5. Seems to be idling a little rough when warm. But no cel. Yesterday while driving normally got a dtm. And checked. Was getting misfires on cyl 5. Cleared the code. Malfunction went away. Was able to drive home no further issues. I believe injector on that cylinder was replaced under warranty around 6 mo ago. Should I change spark and coil and see if problem persist?

Codes when scanned: 140510, 140504, 180101

Also: during injector failure it appears the heat gutted my driver side cat. So I have to do something about that. Was thinking of throwing on race dps. But I don’t want a CEL. Any ideas on that?

[M5Rick]

I would def' change all of the plugs with the standard Bosch gapped at .032 and the associated coil with cyl 5. Not sure about replacing with cat less down pipes, could try a catalyser cleaner like Cataclean.

[6ixcommas]

Originally Posted by M5Rick

I would def' change all of the plugs with the standard Bosch gapped at .032 and the associated coil with cyl 5. Not sure about replacing with cat less down pipes, could try a catalyser cleaner like Cataclean.

Do I have to change them all?

[M5Rick]

Originally Posted by 6ixcommas

Do I have to change them all?

It's always a good idea and why not, with these a one fault thing could lead to another and with the leaky injector it goes without saying the oil was changed also.

[6ixcommas]

Originally Posted by M5Rick

It's always a good idea and why not, with these a one fault thing could lead to another and with the leaky injector it goes without saying the oil was changed also.

Is there a way to check the injectors?

[M5Rick]

Originally Posted by 6ixcommas

Is there a way to check the injectors?

When one is jammed open you smell gas and you can hear it's not running right.
I use injector cleaner every fourth tankful to keep mine in check, I don't think the additives in the gas alone are enough to keep the injectors running sweet in the long term.

[TinCanSailor]

Originally Posted by 6ixcommas

Is there a way to check the injectors?

ISTA has diag routines for checking injector flow rates but if you are looking for bench testing and cleaning you might as well spend the 800 dollars from FCPEuro and buy the bosh or delphi injectors as the labor involved for taking them out, cleaning them and reinstalling is almost as costly, at least that has been my observation for the EU6 injectors.

[6ixcommas]

Originally Posted by TinCanSailor

ISTA has diag routines for checking injector flow rates but if you are looking for bench testing and cleaning you might as well spend the 800 dollars from FCPEuro and buy the bosh or delphi injectors as the labor involved for taking them out, cleaning them and reinstalling is almost as costly, at least that has been my observation for the EU6 injectors.

I feel like I don’t mind taking it to the dealer for injectors as they are still under extended warranty. When I change the spark plug on the cylinder that’s giving me issues would I be able to smell fuel on it ?

[TinCanSailor]

Originally Posted by 6ixcommas

I feel like I don’t mind taking it to the dealer for injectors as they are still under extended warranty. When I change the spark plug on the cylinder that’s giving me issues would I be able to smell fuel on it ?

Honestly I would visually asses. If t is a dark black to glossy black then it is likely running rich. Fuel dumps on this area as normal part of the combustion cycle so you could very well catch a cylinder that just had fuel injected in on it and shut off before the spark and would smell of fuel.