2007 Prius : correct spark plug gap

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by suncitychris, Dec 3, 2024.

  1. suncitychris

    suncitychris Junior Member

    Joined:
    Apr 30, 2016
    3
    1
    0
    Location:
    El Paso Texas
    Vehicle:
    2005 Prius
    Model:
    II
    I have a 2007 Toyota Prius Service Manual; the Manual states the spark plug gap is 0.7 to 0.8 mm (0.028 to 0.032 in.) Numerous threads have posted a spark plug gap of 1.0 to 1.1 mm. Did Toyota issue a technical bulletin with this change? Which gap parameters are correct? Thanks so much. IMG_4344.jpeg IMG_4345.jpeg IMG_4344.jpeg IMG_4345.jpeg
     
    #1 suncitychris, Dec 3, 2024
  2. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,909
    4,005
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    That is interesting. Is that part of the diagnostic procedure for P03xx codes?

    I see that same illustration there in my copy of the manual.

    There are two other places where they show or state 1.0 mm - 1.1 mm.

    upload_2024-12-4_22-13-41.png
    upload_2024-12-4_22-15-54.png
    upload_2024-12-4_22-14-24.png
     
    #2 dolj, Dec 4, 2024
  3. suncitychris

    suncitychris Junior Member

    Joined:
    Apr 30, 2016
    3
    1
    0
    Location:
    El Paso Texas
    Vehicle:
    2005 Prius
    Model:
    II
    Yes, that is correct. What effect might one see if the spark plug gap is reduced from 1.0mm to 0.8mm? Thanks so much for the input.
     
    #3 suncitychris, Dec 4, 2024
  4. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,909
    4,005
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    I don't know, but my feeling is that it would not be a good thing to do.

    Have you considered the possibility that the section of the manual you're looking at is incorrect?

    The plugs are factory-set at 1.1 mm, and I have never had to adjust them, ever. I just check each plug before installing and have never had any problems engine-wise.
     
    #4 dolj, Dec 5, 2024
    Mendel Leisk likes this.
  5. Mendel Leisk

    Mendel Leisk Witness Leader

    Joined:
    Oct 17, 2010
    57,228
    39,500
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    #5 Mendel Leisk, Dec 5, 2024
  6. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,762
    1,769
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    I might expect a slight possibility of occasional misfire under some limited conditions.

    Probably won't affect anything.

    Posted via the PriusChat mobile app.
     
    #6 mr_guy_mann, Dec 5, 2024
  7. suncitychris

    suncitychris Junior Member

    Joined:
    Apr 30, 2016
    3
    1
    0
    Location:
    El Paso Texas
    Vehicle:
    2005 Prius
    Model:
    II
    Gentlemen: thank you for the feedback, it is acknowledged and understood. Appreciate you all!!
     
    #7 suncitychris, Dec 5, 2024
    Mendel Leisk likes this.
(You must log in or sign up to post here.)