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Gen 4 to 3 engine swap air intake coolant lines. Is this correct?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by zoeboi954, Oct 8, 2022.

  1. zoeboi954

    zoeboi954 Junior Member

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    I try looking at other video but not too many are using 4 gen egr. Most are using 3rd gen egr.
    So my question does the coolant line coming from the 4gen egr and the coolant line coming off the thermostat hose connect to the 3rd gen intake coolant lines?
    I know it seem kinda obvious but I just want to double check because the youtube videos that I've seen one guy said it block off one of the ports on the intake and another video a guy's said he used a 3 way pex tee to tap in to the another coolant line...

    20221008_122138.jpg 20221008_124226.jpg
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    Transferring 4th gen EGR has be problematic. Not just bending the exhaust manifold branch to suit, but ongoing. 3rd gen computers' programming differences maybe. Have you already done the pipe bending deed?
     
  3. zoeboi954

    zoeboi954 Junior Member

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    I already repined the egr plug by switching the red and purple wire around. And I already bent the exhaust tube in place. It's ready to bolt on I'm just waiting on a pex tee to come in the mail so I finish the hose connect under the egr.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    I've heard that wire swap was not actually doing anything. Well apart from messing things up.
     
  5. zoeboi954

    zoeboi954 Junior Member

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    I'll have to wait and see when I fire her up. If anything I'll just order another exhaust manifold and put the old egr if it don't work out.
     
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  6. ChapmanF

    ChapmanF Senior Member

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    Abort abort abort. All you have done is disable the EGR valve. Switching those wires simply makes the valve unable to move, while concealing that fact from the ECM so no trouble code is reported. No trouble code also means the ECM doesn't know to protect the engine from nonfunctioning-EGR damage.

    You can find the rest of the details in this post.

    If you let us know where you found that re-pinning advice without also finding the later correction, we should go add the correction there. I thought we had found all the places.
     
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  7. zoeboi954

    zoeboi954 Junior Member

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    I found it on Gen 4 Engine into Gen 3 Prius Partial Guide | PriusChat but I did not read to far and didn't notice he posted not to follow those steps later on. I wish the OP had also edited the original post. But its my fault for not reading the whole thread.

    Alright so now I have a new question. I have the jdm engine version that comes with a outlet above water pump. Right now I currently I have it block off. Can I use that to route coolant lines to the air intake? 20221011_115208.jpg 20221011_120839.jpg
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    I'm thinking to "report" the above post, see if a moderator (likely Tideland) can revise the intitial post of that earlier thread. Could you guys proofread the following, what I'll paste into a report request:

    Kinda complicated:

    This poster followed a procedure from a 2020 thread, where 4th gen EGR components are transplanted into 3rd gen, along with a 4th gen engine. Specifically, it was advocated in the initial post of that earlier thread to swap two wires going to a 4th gen egr valve, in the (misguided) belief it would make it compatible. ChapmanF has confirmed that swapping the two wires really does nothing more than disable the EGR, making it appear there's no problem, since the car's computers just don't get any signals.

    The post in which the wire swap is advocated:

    Gen 4 Engine into Gen 3 Prius Partial Guide | PriusChat

    And the disclaimer, later in same thread:

    Gen 4 Engine into Gen 3 Prius Partial Guide | Page 2 | PriusChat

    Could you please edit the intital post, saying something like this is no longer considered a way to go, doesn't work. Appreciate it's a bit of a tangle. Thanks.
     
  9. ChapmanF

    ChapmanF Senior Member

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    Once upon a time, on PriusChat, you were able to go back and edit any of your own old posts at any time.

    More recently, you'll notice the Edit button goes away on posts you made more than some number of hours ago.

    You can still Report your own old post, and ask a mod to fix something in it, but of course that's more hassle.

    If I remember right, the disappearing Edit button was invented after a past incident where a long-time valued contributor got mad at PriusChat and, before leaving, edited all of his/her old valuable posts to be empty.
     
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  10. zoeboi954

    zoeboi954 Junior Member

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    Ahh i see.... maybe they should have a edit history. That would solve that
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    Ok, reported. :)