Prius Gen 3 strange noise during slow acceleration

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by GabrielD, Apr 29, 2021.

  1. ASRDogman

    ASRDogman Senior Member

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    You are fighting over car farts!!!! o_O:sleep:
     
  2. AW82

    AW82 Member

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    I apologize. I misunderstood your intentions. Since you edited the source I cited, it seemed like you were trying to prove me wrong.

    Your other source because it seems to largely align with other things I've read over the last month or so as I've been researching this topic too. I have seen a lot of documentation that EGR reduces in-cylinder temps, which decreases NOx. The challenge we have around here, though, is that many people then assume that the temperature of the EGR gas before it enters cylinders has some massive importance related to head gasket damage, which is a belief that I have not seen documented.
     
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  3. Grit

    Grit Senior Member

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    we do that every day here in CA, or I should say the politicians here do. Car farts are priority to them, and so are cows.
     
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  4. GabrielD

    GabrielD Member

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    Today I ran a test to learn how paramaters change during road drive.
    Here are screenshots from techstream with 2 speeds, 115 km/h and 130 km/h
    These tests are with a DTC error, P0443 due to connector forgotten not attached...
    Tommorow I will try again, if someone directs me about paramaters to monitor, I will be happy to do as told...
    Second picture is a freeze data when DTC occured...
     

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  5. ChapmanF

    ChapmanF Senior Member

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    Supplying just a screenshot like that makes it difficult for any other reader to find what source you have relied on. In this case it seems to be this article, saying "When outside air combines with the fuel and ignites in the combustion chamber, temperatures can reach above 2500℉ (or 1370℃)."

    It's often appreciated when you identify your own sources so later readers don't have to try to retrace your steps.

    Notice how you got that number as the the temperature reached in the combustion chamber over a small handful of degrees of crank rotation when the combustion takes place. Then, in your question, you use that same number as if it were the temperature of exhaust gas being recirculated. But some interesting things have happened in between:

    • Those burning gases pushed a piston downward, expanding by a factor of 13:1, entailing a corresponding large reduction of absolute temperature.
    • Also, those gases give up heat to the cylinder and head, to be carried away by the coolant.
    • The gases expand further, and drop closer to atmospheric pressure, when the exhaust valve opens, corresponding to a further drop in temperature.
    • They then give up more heat to the walls of the exhaust manifold.
    • Then they pass through an EGR cooler.
    • Then they get mixed in a relatively small proportion into the near-ambient-temperature intake air.

    Key point right there. The important ratio is your fuel to oxidizer: for every gram of gasoline you need 14.7 grams of oxygen-bearing air. Introducing some other gases that are inert doesn't change that ratio; you just end up with less air, and the ECM (which knows it is adding inert gas) injects less fuel to match. You get your 14.7:1 air:fuel ratio and also some other nonparticipating stuff. That gives you a way to achieve less-than-maximum power output without having to close the throttle as far (and saves you the energy loss of sucking across a very closed throttle).

    It doesn't set out to be a reliable source, but to be a source of sources. That means there is a certain skill to using it effectively, which doesn't involve just absorbing things an article says, but checking the citations for those things, and the sources they refer to (and even whether those sources in fact said what the article says they did), and, yes, checking the article history to see whether any claim you might be about to rely on was recently added, perhaps "as a joke".

    As you added your "joke" without any source citation, it ends up being fairly recognizable as not belonging there.

    Using Wikipedia with reasonable care can be a quick way of finding some references to sources that are reliable for a subject you are beginning to study.
     
    #45 ChapmanF, May 7, 2021
    Last edited: May 7, 2021
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  6. ASRDogman

    ASRDogman Senior Member

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  7. Grit

    Grit Senior Member

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    :ROFLMAO:
     
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