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Iridium or Platinum plugs?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Muleears, May 17, 2006.

  1. Muleears

    Muleears New Member

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    Got my classic about two weeks ago. It is nearing 60K miles so I am slowly doing the 60K mileage service. Just changed the plugs and took out NGK Iridiums. Put in Bosch Platinum +4. The ones I took out looked fine (see pic). I just don't know if they were the originals or not. The flash from the camera washed out the tan on the electrodes, they are a little darker than they appear. Anyone know if I would have been better off with the Iridiums?
     
    #1 Muleears, May 17, 2006
  2. etyler88

    etyler88 etyler88

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    Germans and Japanese don't work well together. That is why they lost the war ;) NGK can't be beat for low eletrical resistance and if they looked that good after 60k the platinum durability is not much of a gain. But whatever, if the mpg is the same who cares? Is the mpg the same? How hard was it to access the plug and change them? Anybody know how Gen II compares for plug change?
     
    #2 etyler88, May 17, 2006
  3. tochatihu

    tochatihu Senior Member

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    [attachmentid=3508]<div class='quotetop'>QUOTE(Muleears @ May 17 2006, 11:57 AM) [snapback]257042[/snapback]</div>
    Thanks a bunch Muleears for doing this and posting the image! I am doing a little search right now and will type some blah-blah while it runs. I bought the 2001 Prius new, its plugs were pulled for inspection at 60k miles. They were pronounced "good enough" and reinstalled by Toyota staff. I would like to say that at least this amount of maintenance (60k R&R) is appropriate, because very old plugs can get "welded in" over longer times. I am now at about 87k miles and will not think about the spark plugs until about 100k.

    Unless you have maint records for the car suggesting otherwise, I very much suspect that the plugs you pulled are original. Here is an image from

    http://catalog.drivewire.com/drivewire/bas...part=Spark+Plug

    of what they look like new (appears at the top):

    My opinion is that you have had very little center electrode erosion, and that you ought to hang onto them for possible reinstallation later. Will platinum plugs work OK in Prius? Probably, perhaps but for not as long as the Iridiums, and you are the one who can tell us that later.

    OK, search is coming along now. The specified electrode gap in the service manual is 1.0 - 1.1 mm; call it 40 thousandths of an inch. The recommended (iridium) plug is Denso SK16R11 or NGK IFR5A11 (the latter which you displayed). I have little doubt that you will spark fine with the Bosch platinums. But if you later have poor performance with them or any error codes, stand by to reinstall the iridiums gapped to 40 thou. But don't try to clean them! Gawd I have no idea if that would be appropriate.

    The plug torque spec is 13 foot-pounds, and 80 inch-pounds for the bolts that hold down the ignitors. If you would, please say more about the difficulties, if any, in removing the ignitors. Some of us DIYs are not up to your level yet!

    Etyler, the only one of your questions that I have response to, is that the new model Prius is exactly the same in terms of its spark plugs. If I am wrong in saying so, let the new-model people correct me here.
     
    #3 tochatihu, May 17, 2006
  4. Muleears

    Muleears New Member

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    <div class='quotetop'>QUOTE(tochatihu @ May 17 2006, 05:34 PM) [snapback]257153[/snapback]</div>

    Changing the plugs was really quite easy. You will need a 10mm socket and the appropriate plug socket (I forget the size). First thing you do is move the relay box that hangs on the firewall directly above the plugs. Has 2 10mm screws, one at each end. Don't disconnect any wires just move it out of the way so you can get to the plugs, shouldn't take more than a minute. Next remove the 10mm bolt on the left igniter and remove the igniter/plug boot. Don't pull on any wires, just twist and pull to remove. Next, remove the plug with your plug wrench (or plug socket and extension). I proceeded to complete one plug at a time, after I got the plug out I installed the new one and re attached the igniter before I moved on to the next plug. With the plug wire arrangement the Prius has it would be difficult to get them out of order but I don't take chances with stuff like that. Proceed to change the next two plugs. The only one that gave me any trouble was the far right plug (when facing the ICE from in front of the car). The plug wire is relatively short and the plug boot is long, you may have to bend the end of the boot a little (this should be OK it is rubber). When all plugs are replaced, re-attach the relay box and you are done. You should be able to complete the job in 15 minutes. If your plug tool doesn't have the rubber insert to hold the plug you may need a pair of needle nose pliers to remove the plug from the plug well after it is loose. When installing the new plugs be careful not to cross thread. These have aluminum heads and it would not be good for that to happen. the first several turns on the new plug you should be able to do with your fingers. If you need the wrench to get the plug started it may be cross threaded, back up and try again. It would be a good idea to apply some anti-seize to the plug thread to make them easier to remove (in a few years).

    Just changed them last night and have only had the car about 2 weeks so I can't really tell if the new plugs have any impact on mileage.
     
    #4 Muleears, May 18, 2006
  5. tochatihu

    tochatihu Senior Member

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    Muleears, I just noticed from your posted image of the used plugs that #3 appears cleaner than the others.
    In fact they might rank 3>4>1>2 (in the order you presented them). Would you comment on how they look in person, and which one went with which cylinder? Just a little curious, thanks.

    DAS
     
    #5 tochatihu, May 30, 2006
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