I started getting a sporadic CEL, cyl1 misfire, over the last few weeks. Probably 2 or 3 times, after letting the car idle from cold in the morning.

I took it in to the dealer and he has not found anything wrong and cannot make it happen again. He offered to change either the spark plugs or the charge packs, which are apparently also per cylinder. Any advice?

Thanks!

 

Have you checked the plugs? I would guess the coil would either work or be totally dead... not working once in a while.

 

Dealer says the plugs looked fine but I requested new ones regardless. I thought about getting new charge coils too but apparently those cost a bit more. I am a little concerned about the fact that I saw this repeatedly on one cylinder and never on others, but who knows. I will see when I get it back.

 

Valves adjusted properly? How many miles on the car? Throw out as much info as you can about the car and some of the more knowledgeable guys are here may offer some advice.

 

Move the plug to another cyylinder. It could also be an injector or a valve adjustment. I'd check compression too.

Do the easiest first.

 

Yeah I'd swap the coilpack from cyl 1 and 2 and see if your misfire code comes back on cyl 2. You can do the same with plugs and injectors (but only one at a time so you know what's bad). If the misfire follows the swapped item, then that's your culprit.

All of those items are easy to swap on your own with basic hand tools... Metric Allen wrench, 3/8" drive ratchet, 5/8" spark plug socket w/ extension, 10 mm socket... That's about all you need.

 

Hah, sorry to have dropped so many details, I was a little frantic at that time as the dealer was pushing for decisions. The car has 40k miles and is quite well maintained, regular and roughly recommended intervals. I drive somewhat spirited but not at all crazy, most of the time. The weekend before this started happening I was at Thunderhill and driving at about my skill limit. The car was happy all day, no sign of overheating or any issue what so ever.

The dealer said the valves looked perfect and could not get the code to fire again. So I had them do the spark plugs, since those are fairly wearable either way. I get the car back, and within a day the code fires again! Then it disappears the next day. How does that even happen, I thought CEL codes stayed permanently until explicitly cleared.

Either way, it is back once again. No other symptoms at all. I think I am headed back to the same dealer, hopefully they will cut my bill some slack after the first round did not solve the problem. Swapping coil packs between cylinders as a test sounds like a great idea. I might give that a shot if I am feeling adventurous.

 

Seems like an injector issue, have you let the car sit for extended periods of time? Like a month or more at a time?

 

could be a weak coil going out. it's easy enough to swap a coil from 1 to 2 and from 2 to 1, clear codes, retest.

 

Hah, how did you know? Not recently but over the last few years the car has sat a lot.

I still have no idea how the code cleared itself at one point, but at this point it sure seems like the coil or injector is the culprit.