ignition coil replacement

petitekpetitek Member Posts: 3
edited May 2014 in Subaru
My check engine light has been on (not blinking, just steady) for a month or so. Technician at S ubaru dealer says third cylinder is misfiring and I need to replace the ignition coil; they recommend replacing spark plugs and wires, as well. The ignition coil replacement costs $350; the spark plugs and wires $200. Is this a necessary repair? What happens if I don't do it?Is it dangerous to drive with this condition, or "just" bad for engine-- what are the consequences of letting this go? Thanks for advice.


  • ateixeiraateixeira Member Posts: 72,587
    Yes but AAACK! at those prices.

    I did all of those things on my 98 Forester.

    The ignition coil cost me $80 and it only took two bolts to remove it. I had to remove 4 spark plug wires but mama-mia, $350? That's like $270 for labor, 3 hours? I could probably do it again in 3 minutes. Ok, maybe 5, tops.

    It may be harder to reach on other models, but that still seems crazy high to me.

    Funny thing is the $200 for the spark plugs and wires, with labor, is actually not a bad price. That takes longer and is much harder to access. I probably took an hour, maybe a bit more, so that price actually seems fair.

    I would do the fix because a misfire sends unburned fuel downstream, and that will eventually wear out your catalytic converter, and cost you more than all of the above.

    Fix it, but look in to doing the ignition coil yourself.

    What year/make/model?
  • petitekpetitek Member Posts: 3
    Thanks so much for the detailed reply. I have a 2002 Subaru Forester with 96,000+ miles on it. Catalytic converter was replaced last year (free, just under the wire on government warranty). How long do you think I can safely drive with this condition? We were thinking of doing the work ourselves, as you recommend, but probably can't get to it for a few weeks. Is it safe to drive, in your view, in the meantime?
  • ateixeiraateixeira Member Posts: 72,587
    I would act sooner. You don't want unburned fuel downstream.

    The fact that the old cat failed says it all.

    Do this - order an ignition coil on-line. Should be $80 or so, maybe a tad more nowadays.

    You can change that in the time it takes to fill up your gas tank. Then do the plugs and wires when you can.

    Let me try to find a photo to motivate you...

    Bingo, good pic:


    The ignition coil sits right at the top of the engine. Easy to find because all 4 spark plug wires lead right to it. You unplug those 4 wires, remove 2 screws, replace it with the new one, replace 2 screws, plus in 4 wires.

    Seriously, it's that easy. And there's only one ignition coil, so it's a cheap fix.

    Best of luck, whatever you decide.
  • bigfrank3bigfrank3 Member Posts: 426
    I would save the coil replacement for last, you may not need it unless there is physical damage to it like a crack in the number 3 tower. The same coil pack fires all 4 cylinders so since you are only getting a problem with number 3 I have my doubts.

    I would certainly do the plugs, and if the wires are original, them too.
  • ateixeiraateixeira Member Posts: 72,587
    Pay the dealer $200 for the plugs and wires and then order the $80 ignition coil, which you can do before you leave the dealer's parking lot.

    Problem solved for $280, rather than the $550 originally quoted. Half price basically.
  • petitekpetitek Member Posts: 3
    I do so appreciate this detailed advice! And your input, too, bigfrank3. Very very helpful. We got the car back from the dealer, who assured us it would be fine to drive it for a short time. I'll keep you both updated.Thanks very very much--I feel much better informed now.
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