2 days ago I felt that something isn't right with my Ford. A mechanic told me that he wants to replace all four spark plugs and wires but could I just change the one?

I'm scared that he's ripping me off please help!

  • 1
    Unrelated to the question, but I wonder if plugs and wires are the way to go here. On what basis is the mechanic suggesting this?
    – Zaid
    Dec 8, 2015 at 13:19
  • If your satisfied with my response could you hit the little green check next to it? I like the ego points it give me. lol Cheers! Dec 8, 2015 at 13:29

2 Answers 2


Fear not, he's not ripping you off. Spark plugs are cheap, you change them in sets as you do with brakes or spark plug wires.

You want all of your spark plugs to match and have nearly the same levels of electrical resistance as all of the other plugs.

This make the engine run smoothly. If you had one spark plug firing properly and three that were not you could damage your engine as it would be a bit out of balance.

You want balance in your engine. You want balance with combustion. This gives you efficiency and as well, longevity, with your motor.

This is standard maintenance. I don't think anyone on this site would only change one spark plug on their own vehicle.


It's fine. :-)

Best of luck.

  • 1
    It would be worth clarifying whether the same conclusion is applicable for coil-over-plug configurations (so no wires)
    – Zaid
    Dec 8, 2015 at 13:17
  • 1
    Well answered. When changing parts like that you want harmony throughout the working components within your engine. It's common practice to replace plugs and wires in sets.
    – cloudnyn3
    Dec 8, 2015 at 13:18
  • 1
    @Zaid You had to go there! LOL Dec 8, 2015 at 13:18
  • Of course I did :) Or should we post that up as a separate question?
    – Zaid
    Dec 8, 2015 at 13:20
  • I think you should. I tried tried to find a dupe but couldn't. Doesn't mean there isn't one though. I've been up all night working and am getting a little loopy. It's a good question though, worthy of it's own space. Dec 8, 2015 at 13:24

Here’s how it went for me. One morning, truck wouldn’t start, just kept turning over. It was 5 degrees out. I replaced one plug only. Truck started right up. Another issue I had was bucking on the highway. That still remained. When the weather warmed up I tackled the other plugs and wires as well. Got all but one. It was frozen. The truck ran great for about 20 minutes. Then worse than ever before. I sprayed the frozen plug with PB blaster the day before. That morning, got a good bite on it, turned counter clockwise, then clockwise a few times and went for it. It broke free. Swapped it out with the last motorcraft spark plug. Didn’t check gap. Swapped out the coil pack. Truck is running great with 200,000 miles on it. Not sure if it ran worse because I had one inferior plug and wire that wouldn’t jive with the rest or if it needed the coil pack as well. Also. Cut the hard to fish wires at the coil pack and duct tape it to the new one. It’ll save you 20 minutes as opposed to fishing it thru by hand. Good luck. Hope this helps

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