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Intake manifold, EGR vlv & exchanger replaced

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Deezle, Jun 5, 2024.

  1. Deezle

    Deezle New Member

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    Post replacing these 3 parts to fix the rattle sounds, I am still having issues on startup.

    Its still in the garage bay. I just finished last night, checked all my sensor connectors, etc. I don't get any maint code lights. I smell a lot of fuel and there is quite a rattle noise yet. It smooths out and then comes back, then idles super rough. I shut it down and brought it back online several times to see if it would clean up but it didnt.

    Racking my brain trying to imagine what I missed...

    Thanks in advance for any insight. Brad
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    What’s the miles?
     
  3. Deezle

    Deezle New Member

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    180K miles.

    Update: I failed to reconnect the U shaped Biggish line from the bottom of the intake. I thought I was home free. So I used some MAF cleaner on the MAF sensor. Cleaned all of my elec connections for good measure and blew them out. Buttoned it all up and it still has the rattle sound but it is far improved from the previous startup.

    Feeling a bit defeated on this one. Considering taking it into Toyota to see what they say. But no codes or dash lights at all.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    Coolant level stable? Head gasket coolant leaks start slow.
     
    Brian1954 likes this.
  5. Deezle

    Deezle New Member

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    I will monitor my coolant.

    I am going to change my plugs as well. if one of them is cleaner than the others I suppose a HG is likely.

    Thanks!
     
    Mendel Leisk likes this.
  6. Deezle

    Deezle New Member

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    Changed my plugs and all 4 had a decent looking color. None of them were washed either, so Id have to rule out the head gasket bothering the cyl fire to disrupt idle. Or am I missing something?

    I notice when the engine is finishing its cycle going back to battery the noise stops while the engine is running for about 10 seconds before the shutdown to battery.

    The noise is not the pronounced knock. It is more of a rattle that sounds like a loose heat shield on a converter or something.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    The preferred DIY head gasket check is to pressurize the engine coolant (requires some sort of air pump and attachment to reservoir), then inspect combustion chambers with boroscope; you’re looking for:

    1. exceptionally clean piston tops.
    2. Coolant tears running down cylinder walls.
     
    Deezle likes this.