Misfire trouble

[macdude357]

So I was at the track the other day and noticed my "Service Engine Soon" light came on during a session. I didn't think much of it and just figured that my mechanic just forgot to reset the mileage for my oil change. Two sessions later, I pull into the paddock and after hanging out for about 30 minutes, I went to start the car up to get some gas and it started running really rough and actually stalled (DCT so no, it wasn't me). I started it back up and it ran really rough and I got a CEL and the car went into limp mode. I checked the codes and found multiple issues including misfire on cylinder 1 and 2, increased emissions, etc (stupid me forgot to save a report).

I decided to go ahead and pack up the car and was going to call for a tow but after sitting for 45 minutes or so, the car started up OK and I was able to make the 250 mile drive home without an issue. I then remembered that I got an SES light a month ago as well when at the track but no limp mode. So I'm thinking that what the issue is, it's slowly getting worse.

Anyone have any suggestions as to what might cause this only when the engine is hot (my oil temps usually hit the 250-260 mark during a session)?

The car is due for plugs soon, so I thought I'd just do that for now and maybe see if there is anyway to test the coils while changing the plugs. Seems that if it were a vacuum leak, plugs or something like that it wouldn't just be limited to just a couple of cylinders or just when it's hot.

Any suggestions are appreciated.

[deansbimmer]

When failing, coils are known to act up when hot or at high rpm then act normal when cold or at lower speeds.

No idea otherwise, could be a hundred things causing it. You'll need to have it taken in for diagnostics.

[///M248]

Sorry to hear about your issues.

This may sound stupid, but try throughly charging your battery. If it’s old it and depleated / not holding a charge it can cause electrical gremlins like you’re having.

Cheap way to rule out something basic.

Good luck!

[macdude357]

Originally Posted by deansbimmer

When failing, coils are known to act up when hot or at high rpm then act normal when cold or at lower speeds.

No idea otherwise, could be a hundred things causing it. You'll need to have it taken in for diagnostics.

Thanks, that is exactly the type of info I was looking for.

[eatsleepboost]

Yea I think change all plugs, coils 1+2 and put some miles on it. Not going to be easy to diagnose as it doesn't do it often and he can drive hundreds of miles ok.

You could also just do the plugs and move coils 1+2 to other cylinders, say 3+4 or anywhere easy to access and remember or mark them. Clear all codes and continue your normal routine with the car. If it happens again check for codes to see if it chased one or both coils. You could buy a coil or 2 and keep it in the trunk for that occasion and swap it out right then. Might want to throw some thin gloves in the truck too since the engine will be hot if you need to change it