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PCV valve replacement

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by dmckinstry, Aug 5, 2007.

  1. dmckinstry

    dmckinstry New Member

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    A question for Galaxee or anyone else who knows!

    I know where the PCV value is, but I can't see it. Is it possible to get at it by only removing the relay box and wiring harness above the hose to the PCV value, or does the cowling (i.e., the assembly that has the wiper arms shafts going through it) have to be removed?

    Galaxy says its a simple job, but I don't want to get into it, until I know about how long it will take. I've had that cowling off before, when installing my block heater. I don't want to get into it, and then discover my wife needs the car right away.

    Thanks for any help.

    Dave M.
     
    #1 dmckinstry, Aug 5, 2007
  2. hobbit

    hobbit Senior Member

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    The cowl almost definitely has to come out [easy], and then if you
    remove the air-box and undo the bolts around the top/back holding
    the main engine wiring harness down, you'll be able to bend that
    up out of the way and access the PCV on the end of the rear valve
    cover "bump". Last time I was in there I pulled it and gave it a
    shake to hear the little valve rattling and figured it wasn't crapped
    up. I'd think that you could be in and out of there in an hour,
    but if you haven't done it before and want to go carefully, allow for
    a bit more time.
    .
    _H*
     
    #2 hobbit, Aug 5, 2007
  3. galaxee

    galaxee mostly benevolent

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    #3 galaxee, Aug 5, 2007
  4. dmckinstry

    dmckinstry New Member

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    <div class='quotetop'>QUOTE(hobbit @ Aug 5 2007, 02:05 PM) [snapback]490961[/snapback]</div>
    Thanks Hobbit.

    I may wait until next weekend, but will definitely do it. I already bought a replacement. It was only about $11 including tax, so I'll put it in anyway. The old one is probably OK. I've never seen an error code on my CanView (at least since I put it in near the beginning of the year), but I do have a fuel dilution issue. Could that be caused by a partial clogging, even without an actual "failure" of the valve? I've never noticed oil on the engine air filter, and I haven't studied enough whether a spring out of specs would cause too much fuel vapor to enter the crankcase, but have read that fuel dilution could be associated with a "bad" pcv valve. I don't know why my car should have excessive blow by. I've never even completely floored the throttle, although I have maintained 65-70 mph on some fairly steep climbs in the mountains, which has indicated WOT on my CanView. However, that has only happened rarely.

    Oh. About 55k on the car now, but I started doing oil sampling around 40k and there has been fuel dilution and reduced viscosity on nearly every report. I've started using Mobil 1 and will see if that has any effect on the viscosity at 5000 miles.

    Dave M.
     
    #4 dmckinstry, Aug 5, 2007
  5. jayman

    jayman Senior Member

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    <div class='quotetop'>QUOTE(dmckinstry @ Aug 5 2007, 05:03 PM) [snapback]490985[/snapback]</div>
    David

    After comparing the used oil analysis of my Prius, which is now strictly a city short commute vehicle, to yours, something is amiss. The PCV is designed to keep the valve train clean by getting rid of the oily vapor you would normally have. Especially in cold weather operation, that makes a big difference in valve train sludge buildup.

    I'm not comparing apples to apples, but with my 1984 Ford F-150 and 302 V8, when I used to drive it in cold winter the PCV valve would have frothy white stuff on it. Using a HD engine oil like Mobil Delvac 1 5W-40 or Esso XD-3 0W-30 made that go away.

    With the amount of fuel dilution you have, you really are going to have to keep an eye on things. You clearly are *not* a candidate for extended oil changes. One thing to keep in mind is that with conventional oils, a solvent like gasoline can really muck up the polymer additives and create deposits in the ring land and under the piston crown land. A synthetic with good detergents, or a HD oil, will prevent that.

    I'm still unsure about PCV problems. With my former 2000 GMC Sierra and Vortec 5.3, there was a TSB on the PCV valve. It was *too* aggressive, and actually caused oil consumption due to sucking oil off the top of the heads. The General's "solution" was to put in a PCV "valve" that was actualy a fixed oriface. That resulted in a whistling sound just the right pitch to drive me insane

    jay
     
    #5 jayman, Aug 7, 2007
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