gapping spark plugs- required?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ericspoor, Jan 5, 2019.

  1. ericspoor

    ericspoor Member

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    i changed the spark plugs with oem denso plugs, but i didn't occur to me that they might need to get gapped first. does anyone know if the oem plugs are pre-gapped?
     
  2. SFO

    SFO Senior Member

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    Yes.

    Which plugs did you purchase?
     
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  3. ericspoor

    ericspoor Member

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    to be honest i cant remember. they were denso brand. autozone's program indicated they were the oem plug, which may or may not have been accurate.
     
  4. Mendel Leisk

    Mendel Leisk Underfoot

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    Most if not all plugs come pre-gapped, and especially with the high-end long-life ones, the plug manufacturer often will have a warning against adjusting the gap. The auto manufacturer spec's a plug, and will invariably list the gap that plugs come with, as the correct gap.

    That said, it doesn't hurt to check the gap. That's been the case with the last few cars we've had, and when checking new plugs I've never seen incorrect gaps.
     
  5. ericspoor

    ericspoor Member

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    Thanks for the info! a follow up: does the coil pack boot require dielectric grease? that was another step i didn't take and only read later that it is a good idea to do.
     
  6. Mendel Leisk

    Mendel Leisk Underfoot

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    Some swear by it. When I'm not sure, I consider the current condition. They didn't apply any grease at the factory, and it's been ok so far.
     
  7. brdmb

    brdmb Junior Member

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    Yeah, if they're platinum no need to gap - they're pre-gapped properly. I've never used grease on my Toyotas' boots/coils and have yet to have a problem

    Posted via the PriusChat mobile app.
     
  8. Brando714

    Brando714 Junior Member

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    PLEASE READ! Wanted to give you guys a heads up on those spark plug gap gauge that I just noticed today before installing my plugs. I purchased mine from Autozone and the gap of the plugs straight from the box were off by a lot so I was kinda stressing out about having to adjust it then I noticed, there's a barcode sticker right where the ground electrode and the center electrode runs along on the gauge. This not only gave the false reading but also upon pealing the sticker, left an adhesive and you def don't want that touching your copper core or anywhere else for that matter so just be careful. Hope you guys read this and keep that in mind from my experience of what could've been.
     
  9. dolj

    dolj Senior Member

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    If they're iridium (and the correct part number) no need to gap - they're pre-gapped properly. In fact, the iridium tips should not be touched with feeler gauges, as they can be damaged.
     
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  10. jerrymildred

    jerrymildred Senior Member

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    I knew about not gapping them, but did not know this! :eek:
     
  11. edthefox5

    edthefox5 Senior Member

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    Op multiple post on same subject.
     
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