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Gen4 EGR fate?

Discussion in 'Gen 4 Prius Technical Discussion' started by rosencrantz, Nov 2, 2018.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    They're plain steel (gaskets 2 and 3 in illustration above), pretty sure. I think it's just Toyota being a little over-the-top on those.

    Even with the compressible ones I've been cavalier: I've had the intake manifold off twice, the throttle body maybe three times, never replaced any gaskets. I'd think age/miles is a factor. Obviously replacing all is the rolls royce for safety.

    Yeah, 4th gen owners, especially those with miles going up: do yourself a favour and have a look at that pipe.
     
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  2. kithmo

    kithmo Couch Potato

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    In all honesty, I too have only replaced gaskets or seals when I deemed it necessary. Such as ones that I have damaged taking off or that were leaking before or ones that would need a lot of disassembly to replace at a later stage. So common sense prevails in this throw away society.;)
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    I took the EGR valve off a Civic a while back. It had a metal gasket, but it had a coating, which half stayed with the gasket, and half stuck to the engine. That was obviously knackered and I replaced. But plain steel gasket, no nicks/bends, looks like new?

    Again, even the flexible plastic O-ring style gasket at the intake manifold end, I didn't replace. If it looked seriously compressed/stressed I would.

    This is all subterfuge by fourth gen owners though: someone's got to have a look at that pipe, report, lol.
     
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  4. qettyz

    qettyz Active Member

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    This is not good news that inverter has to be removed to gain access to EGR valve. Sounds much more difficult job than Gen 3.
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, looking at engine bay pics, it looks pretty packed. (n)
     
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  6. Raytheeagle

    Raytheeagle Senior Member

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    Don’t forget it’s the non-diy mechanic performing the task and getting paid to do so ;).

    As an example, I did the first egr cooler swap on our 2010 WITHOUT removing the windshield wiper cowling :eek:.

    But until someone actually does it and gives us info, it’s all supposition (y).
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    We wait...

    One sand-pounder: Toyota seems to have abandoned the print Repair Manual, and it's pdf iteration. Maybe someone with a subscription can download/post the relevant online sections, see what it says.

    That said, Toyota seems to have a "you need to remove your pants to pee" attitude. The 3rd gen repair manual oil change instruction for example, says to remove the full engine underpanel (which I readily do) AND the panel ahead of it.

    So yeah, maybe it'll take a few DIY forays to know for sure.
     
    #27 Mendel Leisk, Mar 4, 2019
    Last edited: Mar 4, 2019
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  8. farmecologist

    farmecologist Senior Member

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    I'm a bit skeptical too that the Inverter needs to be removed.

    Looking at the engine pic here :

    Gen4 EGR fate? | PriusChat

    It looks like the EGR *should* be relatively easy to get to.

    However, that is just a picture of the engine itself. It is probably a far different scenario when viewed in the engine bay. (y) Even though they *did* shrink some of the components, they also slammed the 12V battery in the engine bay..so maybe overall less 'room to work'?
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Not in that picture (which I'm guilty of posting) is the very nearby inverter. Google 4th Gen Prius engine bay pics, and you'll see it's pretty crowded.
     
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  10. farmecologist

    farmecologist Senior Member

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    Yep..it does look very crowded. Looks like fact that they squeezed in the 12V battery is certainly a culprit.
     
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  11. qettyz

    qettyz Active Member

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    Quite nice view of EGR system on this another great WeberAuto video of EV cooling system.
    Starts around 4:20 from side view to engine bay view where it can be seen that accessing those can be difficult for sure.
    FFD55004-0A14-467C-8732-B10FCEFA071D.png 5BA8DE22-64F0-426E-9F2D-A487D43A8C82.png


    5:25 for closeup of egr valve and egr cooler on engine bay.
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    Good video, and access to the EGR pipe actually looks easy. For the entire system, maybe not so much, without inverter removal? Still I'd bet it could be done.

    It's larger diameter than third gen? That might be telling. I think the cooler too has an significant increase in cross-sectional area.
     
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  13. farmecologist

    farmecologist Senior Member

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    After studying the video, I dare say that the *location* of the EGR cooler is in a better place than the Gen3. Looks like no need to remove the cowling on the Gen4? You may be right though..given the proximity of the inverter, there may not be enough clearance to get at the bolts and such without doing something with the inverter.
     
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  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Do we dare to think spark plugs could be removed without cowl removal too?
     
  15. alanclarkeau

    alanclarkeau Senior Member

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    Toyota Gen4 publicity said:
    upload_2019-3-7_11-10-40.png