So another ignition coil went bad on the S2 while on the road today but I was prepared this time as I kept the old ignition coils that were still in working order in the trunk just in case! My question is what can cause a relatively new coil to go bad so quickly. I only put about 5k miles on this particular coil and it doesn't seem to be in too bad of shape as far as I can tell. The only notable thing I can think worth mentioning about it is that its an Autozone coil but I also heard that these are unbranded Denso coils.

 

Not all Autozone coils were rebranded Denso, I think the ones that were say Denso on them. I bought actual Denso coils off Rock Auto For ~$35 each. I want to say that replacing all is a good idea vs just one.

Also you may want to check your spark plug torque.

 

+1 keep spreading the truth -- not all Autozone may be Densos, but the ones that are, are labeled as such (and/or have a "Made in Japan" sticker on them).

 

Ah, that I did not know. The one pictured above is definitely unbranded... Thanks for the heads up. Hopefully, this one was just a bad autozone quality dud then.

 

if you ever do an internet search of s2000 coils you will see quite a few models that are not made by Denso, and searching the reviews on them shows lots of early failures from people that purchased them. My guess it is a cheap China knock off, any ones made by Denso still come from Japan if I recall. The Densos I bought a few months ago weren't very expensive and were made in Japan and branded as Densos, for such a key component you don't want to go cheap either way, a bad coil can ruin your day in the S2000.