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Rust where is should not be

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by johnnychimpo, Aug 20, 2008.

  1. johnnychimpo

    johnnychimpo Active Member

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    Hello I am 3 thousand miles away from a 100k so i was doing some maintenance and i was checking the plugs to see what they look like and this is what i found on the first cylinder closest to the synergy drive. is there any reason in the world why this would have water to make the plug rusty like this besides a blown head gasket? the car runs great by th way " quick history i got the car with 70k from toyota certafied dealership i also got extended warenty for anothe 100k so im good up to 170k. coments sugjestion besides taking it to the dealer that is the obvious next step

    ps sorry i cant seem to load an image cause i dont have it on a url
    is there another way to post an image

    thanks
     

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  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The "first cylinder closest to the synergy drive" is cylinder #4.

    If you wish, you can upload a photo file by "Go Advanced", and look for the file attachment utility.

    The usual reason why a spark plug would be rusty is because water entered the spark plug well. You've probably noticed that only one small bolt holds each spark igniter to the valve cover. The rubber O-ring around the igniter does not form a perfect seal.

    Water can drip down from the cowl onto the engine. Or, if you wash your engine, this provides another possible way for water to appear on the valve cover, then enter the spark plug well.

    What does the spark igniter look like? Is it also corroded? Are there any burn marks upon, or cracking of the plastic body? If so, then the igniter should be replaced.

    If your extended warranty plan was provided by Toyota, then it should expire when your odometer reaches 100K miles. I'm not aware of an extended warranty plan that provides coverage beyond that mileage. If yours really does so, please scan the terms of the plan and post as a .pdf file.
     
  3. dogfriend

    dogfriend Human - Animal Hybrid

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    A blown head gasket would not cause the rust shown in your pictures. If a head gasket leaks, the coolant will either leak into the combustion chamber, into the crankcase, out between the cylinder head and block or some combination of the three.

    I agree with Patrick that the rust is due to water getting into the spark plug well.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Now that you've provided photos, I suggest that you replace the four spark plugs with the correct NGK or Denso iridium plugs (see owner's manual for the correct model numbers), and clean off the igniter that was in the photo, using a couple of paper towels moistened in paint thinner. Since the igniter produces high voltage, do not use water, and make sure the igniter is perfectly dry before reinstalling it.

    You should also clean out the spark plug well the best you can, using more paper towels and paint thinner. Not too much paint thinner - you don't want liquid to enter cylinder #4. Make sure the spark plug well is dry before you reinstall the spark plug and the igniter.

    What does the high voltage terminal in the bottom of the igniter look like?

    If you cannot remove the rust stains, if the high voltage terminal is corroded, or if you find cracks or burn marks in the plastic, I suggest that you replace the igniter now so that you won't have a misfire problem later.
     
  5. richard schumacher

    richard schumacher shortbus driver

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    The dealer should have done this, but confirm with a dealer or with Toyota USA (they have a toll-free number; have the VIN handy when you call) that all applicable TSB (Technical Service Bulletin) repairs and modifications were performed on this car. Some early versions needed to have the hood gasketting replaced to prevent water entry.

    It's also possible that a previous owner was a nutcake who washed the engine with a garden hose.
     
    2004priusgal likes this.
  6. 2004priusgal

    2004priusgal Junior Member

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    would that earlier version include for 2004 prius? ill look
     
  7. 2004priusgal

    2004priusgal Junior Member

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    2004 at 160,000 mi...
    gasket replaced.
     
  8. VFerdman

    VFerdman Senior Member

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    2004 with less than 100K miles?! Wow!
     
  9. Skibob

    Skibob Senior Member

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    Thread is from 2008