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Quick Engine / Throttle Question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by BeatleBob, Mar 28, 2015.

  1. BeatleBob

    BeatleBob Junior Member

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    Hi All,
    This issue came up in the course of working on cleaning the throttle and changing the engine air filter on our 2004 Prius earlier today. Is it normal that there would be engine oil collecting in the intake plenum directly below the throttle body? I'm seeing enough oil there that it is covering the bottom of the plenum. Could engine wear cause the PCV system to drop oil from the crankcase vent where it comes into the throttle body? Is this a normal 150K mile condition? It is not full of oil, but enough to make a shiny puddle at the bottom of the plenum.
    Thanks as always,
    Beatle
     
  2. m.wynn

    m.wynn Senior Member

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    Vehicle:
    2014 Prius
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    Three
    Completely normal with the gen2, Bob. Many a PCer who has cleaned their own throttle body and posted about it has noted it. Although PCV is the seemingly obvious candidate for cause, it's not clear that engine wear is. You can find examples of young, low-mileage Prii right along side "mature" cars like yours and mine. It's likely they do this from birth. The amount of oil you describe is exactly what I see in my 07 w/145k. Some here like to mop it out of there but I don't bother. It's a little perplexing but a non-issue.
     
  3. AzWxGuy

    AzWxGuy Weather Guy

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    I "mopped" out the intake manifold of my 2008 twice using a dangerous but successful method you can find if you want in my previous postings. The fluid was more than just engine oil, which I suspect arrived there via the PCV. Some portion of it was a clear fluid most likely accumulating in the manifold due to the Atkinson cycle. It had a slight odor of gasoline but was not as volatile. I felt better getting it out of there but it probably makes no difference if you leave it there.