1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Spark Plugs (LOL)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Gen2_Accel, Nov 17, 2022.

Tags:
  1. Gen2_Accel

    Gen2_Accel Junior Member

    Joined:
    Nov 9, 2018
    31
    8
    0
    Location:
    New Holland, PA
    Vehicle:
    2007 Prius
    Model:
    Touring
    Denso SK16R11 (old). NGK IFR5T11 (new). Both iridium tip.

    Denso's lasted ~75k mi, way too low.
     

    Attached Files:

  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    7,791
    1,348
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    It looks like they were running a little rich or something your whole electrode is missing or worn down completely flat they look like real densos. I mean generally they speak of these plugs being like 100,000 mi plugs so $25,000 mi off if you're running too rich or too lean and burn them up or what have you that doesn't seem horrifically bad.
     
  3. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Are you sure that the Denso plugs weren't counterfeit?

    I've seen many pictures of counterfeit plugs on the internet that look like yours with burned off electrodes that were cheap replacements for precious metals like platinum, iridium, etc.



    Posted via the PriusChat mobile app.
     
  4. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,206
    1,337
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    First thought is that those Denso plugs are/were counterfeit. I have never seen any (good) spark plug wear the tip completely away like that.

    Side note, it looks like those plugs had high voltage arcing down the sides of the porcelain insulators. If so, then the insides of the coils will have similar tracks. This can cause continued arcing and misfire which will burn tracks into the new plugs.

    I would replace all the coils and the plugs at the same time, only with parts from a know good supplier.

    Posted via the PriusChat mobile app.
     
    #4 mr_guy_mann, Nov 17, 2022
    Last edited: Nov 17, 2022
  5. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,058
    5,783
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    Yup....most likely was a 4 pack of Amazon or eBay sk16r11 plugs that cost about 15-20 bucks....
    Straight from the China counterfeiting machine...
     
    Gen2_Accel likes this.
  6. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,072
    14,974
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Of more concern with some of the counterfeits is having the electrode not so much wear away as fall off, and bounce around trashing the cylinder and piston.
     
  7. Gen2_Accel

    Gen2_Accel Junior Member

    Joined:
    Nov 9, 2018
    31
    8
    0
    Location:
    New Holland, PA
    Vehicle:
    2007 Prius
    Model:
    Touring
    Been awhile for a mem recall of the order but I think u r correct. Chi-com Denso knock-offs...
     
  8. Gen2_Accel

    Gen2_Accel Junior Member

    Joined:
    Nov 9, 2018
    31
    8
    0
    Location:
    New Holland, PA
    Vehicle:
    2007 Prius
    Model:
    Touring
    Fair observation! The coil packs looked like new on the inside- quite clean. Hard to believe a sneak path would be resident; unlike my F150 coil packs which were an *awful* design, requiring constant TLC. I digress- the (F150) dielectric grease fell from the coil pack spring to the spring-plug interface, and viola, poor electrical contact! POS design.
     
  9. mlsimmons

    mlsimmons Junior Member

    Joined:
    Dec 19, 2019
    23
    2
    0
    Location:
    Everett, Wa
    Vehicle:
    2005 Prius
    Model:
    N/A
    so how can you tell that they are counterfeit?
     
  10. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    7,791
    1,348
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    You can look on Google and it'll show you the markings that you need to be looking for and if they are faked how they're different when they're faked and shows you how to tell different ways for different brands Asian versus what were American like champion versus nip and then so versus NGK and Bosch...
     
  11. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,447
    3,751
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Just so I don't have to deal with counterfeit issues, I just buy my plugs from the dealer even though they cost me NZ$32 (plus 15% tax) each. In the US, the same plugs are, at the moment, on sale for US$9 at Olathe Toyota. I could also get NGK IFR5T11 for NZ$28 (+ tax) each from my local auto parts store if I wanted to save a couple of bucks.

    But in any case, I would suggest only buying your plugs from a brick-and-mortar store and only buying the correct Denso or NGK plugs.
     
  12. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    6,688
    6,375
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    The pictures in the original post show a very bad failure condition. Something that should never happen to real plugs from any brand.

    The best way to protect yourself is to buy them from a real store in person.

    There are many reports of counterfeits on eBay and Amazon, but no reports of counterfeits making it to the parts counters of neighborhood parts stores.
     
  13. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    7,791
    1,348
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    I used to be able to call denso's North American office and get sample sent to me in short order those were the good old days. Other than that buying and brick and mortar stores doesn't really net you anything If you don't know what you're looking at they could be passed on to you through a brick and mortar store and it has happened and will continue to happen If you can't see the forest for the trees or you have no interest then you're probably going to get taken just like everything else in life thanks loans car loans all of it You don't know what you're getting into well you might get taken but that's the American way now for the most part everybody's getting taken in some form or another especially if you want something like a bank loan a new car a mortgage You're getting taken on one end of the scale some kind of way It just may not seem like it the moment you're signing the papers but these are things you learn over time as you keep having to do these things over and over again a few times.
     
  14. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,447
    3,751
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Any brick-and-mortar auto parts store worth its salt will care about its reputation and therefore could not risk selling counterfeit parts. They have supply chains that are auditable and accountable. Could it happen on an occasion, maybe but I doubt it. Any store that got a reputation for continually selling fake goods would be out of business pretty quick. Certainly professionals would not use them.
     
  15. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    7,791
    1,348
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    I agree I'm just saying they slip through the cracks so we should know how to identify them but maybe not.
     
  16. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,058
    5,783
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    Best way to ID them is when a deal is too good to be true, but a lot of sellers caught on to that and actually charge the same price as the real ones or even slightly more. Some buyers believe a higher priced product must be real. Tricky stuff now-a-days, especially since the "visual quality" of the fakes is getting better and better.

    I think most people will find out when the plugs only last 25-30k miles before they start misfiring from excess gap..
     
  17. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,206
    1,337
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    The weird green paint on the hex base. That and decades of experience with "known good" spark plugs.

    A badly worn plug might have a little nub remaining above the porcelain and the ground electrode will be eroded away, but the center electrode doesn't "disappear" completely.

    Posted via the PriusChat mobile app.