Gen 3 Motor Issues - Piston Soak - Blowby Pressure

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Paladain55, Nov 14, 2022.

  1. Paladain55

    Paladain55 Active Member

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    Yup:

    e85 cleaning as posted above, cleaned intake ports, intake valves, fuel injector tips, poured some e85 through the lower pcv connection to clean out the built in oil trap, and did the open air crankcase ventilation conversion with the open air breather can and 5/8" breather lines ran as short as possible, and swapped to high mileage full synthetic 0w-20 motor oil changed every 5k.

    I would say the breather can probably didn't do much, so it may or may not be useful to follow that one.

    But the e85 cleaning as i did and swapping to high mileage full syn changes every 5k are huge. Extra cost on these is like $5 for the cleaning and maybe $2 every oil change.
     
  2. Paladain55

    Paladain55 Active Member

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    Per an old post from me:

    "I was gonna add that I did a piston soak at 203k. Made the car like brand new again. Basically as good as most average new cars can be.
    Went from:
    Consuming 1/2 quart: every 400 miles on the interstate. Maintaining 75 mph through 15% grades is tough.
    Around town 1 quart: every 4000 miles trying to keep the car at 2100 rpm for pulse n glide like driving.
    Averaged (55% city, 45% hwy): A quart every 2500 miles if it was a busy tank on interstate 1500 miles.

    After piston soak at all rpms and all conditions car now consumes a quart every 10,500-11,000 miles. But oil is changed at around 5000 miles so it ends up being around a little bit less than 1/2 quart every oil change. Now I can strap kayaks to the roof, do interstate trips, and tow the occasional trailer with a fridge or jet ski no problem.
    Also, installed an oil catch can and swapped to high mileage motor oil to combat weepy oil seals.

    Car runs like brand new now."
     
  3. Bill Norton

    Bill Norton Senior Member

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    This part of your mod is smelly, dirty and probably illegal. I'll pass.:oops:

    The 'high mileage' oil may just have a bit more 'seal swell' ingredients.
    With a proper PCV there is a slight negative pressure within the crankcase, which may lessen oil being pushed past any seals.
    You might even have less oil consumption with a proper PCV system because of that.
     
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  4. Paladain55

    Paladain55 Active Member

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    Update: Still going well. EGR delete. Open air pcv. Never any oil in it. Just water. Most recent oil change: Burned 13oz in 5200 miles. Car is great.
     
  5. Bill Norton

    Bill Norton Senior Member

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    This is a giant leap back to the 50's and early 60's.
    When did the PCV system become the law of the land,,, you law breaker? :unsure:
    I'll pass. I may install a catch can at some point.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Sadly, even an unvented OCC is deemed unlawful, simply because it’s an unauthorized, unregulated mod. I can see the logic, but it’d be good to have some approval process.
     
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  7. rjparker

    rjparker Tu Humilde Sirviente

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    It's better to have it built in and draining to the sump as in newer cars. Otherwise an untended aftermarket OCC can blow engine seals.
     
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  8. Paladain55

    Paladain55 Active Member

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    I kinda thought the same thing at first. But it does great at evacuating water and combustion byproducts from the oil. Oil still comes out very clean. Most politicians don't follow the rules they write anyways. I basically have no emissions laws on my boats or airplanes if it makes you feel better. Just cars.
     
  9. Bill Norton

    Bill Norton Senior Member

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    1. That's called "What about-ism". Not an excuse for farting in public.

    2. Well that has got to change. I hate the smell around marinas. And it's really bad water skiing behind some of those old stinkers. I feel bad for kids tubing behind stinkers. I know it makes me cough and clear my throat for hours after doing that.
    All newer boats have fuel injection. For a few bucks more they could have catalytic converters. (y)

    And the smell around small airports is sort of poisonous due to the use of LEAD in the Avgas.
    Unacceptable.
    Is it just impossible to make Lead Free Avgas? Many are trying, , and for some reason failing.
    I just don't understand. And yet I understand the problems with the antique engines used in aviation.

    Don't bring babies and young children to small airports. If you must, keep them upwind from the toxic exhausts of planes.
    There is no safe level of lead.
    Jet fuel, (diesel) is fine.;)
    I've spent my entire career in aviation. (y)
     
    #89 Bill Norton, Mar 23, 2025
    Last edited: Mar 23, 2025
  10. Bill Norton

    Bill Norton Senior Member

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    Well actually....:sneaky: ;)
    A proper PCV is 'positive' crankcase ventilation. Which means a positive flow of clean replacing the dirty.
    There is no flow in your crankcase. The blow-by gasses and moisture just sits there until it's pushed out the inlet hose connected to the air filter area or out the pcv valve only as more blow-by is created.

    With a proper PCV system the crankcase is always at a slightly lower pressure due to the PCV valve sucking the air out to the intake manifold flow at a lower pressure and replenished from the air filter hose.
    Do you still have the PCV valve in place? It may not be flowing anything 'out' and all the blow-by makes its way out to the air filter area. Is that area getting oily on you car?
     
    #90 Bill Norton, Mar 23, 2025
    Last edited: Mar 23, 2025
  11. Paladain55

    Paladain55 Active Member

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    Yup. Its just crankcase venting now. So to state I don't care about environmental impacts. But it works for years now. Also pcv just means the crankcase is under vacuum supplied by the intake manifold. They still essentially boil off and fly out the top vents. I know there is a small benefit to the vacuum system, mostly emissions related, slight reduction in pumping losses and friction. Doesn't make a measurable difference in real life. Oil doesn't ever get in the catch can just water with a slight tint to it. Faint gas/oil smell to the liquid. Looks like a light tea. But after the ring cleaning my car doesn't drink oil so i imagine this is why. I just got tired of knocking at start up on cold mornings.

    And nah i don't have the pcv valve. Just 5/8" straight barb connectors in place. Hole can runs 5/8" heater hose in short of runs as possible to the catch can.