How to remove the EGR valve/cooler

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by Jdpl76, Aug 3, 2024.

  1. Jdpl76

    Jdpl76 Junior Member

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    I need to replace the EGR vavle and maybe the cooler.. The problem is that a tutorial I watched is not the same as my year and I don't see any videos of a layout like my 2016 Prius hybrid.

    Directly to the right of the EGR on my car is the inverter which seems to be in the way. Will I need to remove the inverter to replace the EGR vavle?

    Thank you.
     
  2. Mendel Leisk

    Mendel Leisk Witness Leader

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    What's the miles? Gen 4 EGR systems have proven VERY butlet-proof. @Raytheeagle did his (did require a inverter shift IIRC).. @jerrymildred did one at the shop he worked at, customer request. To best of my recollection in both cases cleaning proved unnecessary; the systems were still very clean.

    Here's Jerry's post:

    Gen 4 EGR cleaning at 360,000 miles | PriusChat
     
    #2 Mendel Leisk, Aug 3, 2024
    Last edited: Aug 3, 2024
  3. Jdpl76

    Jdpl76 Junior Member

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    150,000. I took a putty knife and blocked the path of the EGR took her for a test drive and the problem immediately went away. No more shaking on acceleration.
     
  4. Jdpl76

    Jdpl76 Junior Member

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    Also I want to add that I recently changed the oil and may have overfilled the oil then put about 600 miles on the odo. I read somewhere that if we go by the dipstick it is overfilled and to fill it 3/4 below the full mark is a good practice but I filled it to the full line. I already bought the part 04004-58137 for $250 annd this is just for the valve. Before I proceed I just had a few more thoughts and questions.

    Based on what you shared I could be wasting my time and find a squeaky clean EGR valve since the gen 4's really shouldn't have a problem with clogged or sticking EGRs..

    Is is likely that my EGR could have gotten prematurely clogged at 150k because I overfilled the oil recently ?

    Do you believe my diagnosis is conclusive enough to move forward with replacing the EGR valve?

    Do you think I need to replace the cooler also?

    What else could it be based on the test I did and how it ran with a bypassed EGR?

    Thank you
     
    #4 Jdpl76, Aug 3, 2024
    Last edited: Aug 3, 2024
  5. Mendel Leisk

    Mendel Leisk Witness Leader

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    My hunch is it’s all good. When refilling oil i just put in the specd amount, leave it a few days before checking dipstick. It’s invariably about 3~5 mm below top pip. You’re probably a bit overfilled, but not serious. Gen 3 is a “little” different, but almost the same engine.

    with the EGR, I’d sleep on it. So far very few Gen 4,reports, all saying not to bother; it seems Toyota learned a lot from the Gen 3 beta testers.
     
  6. Jdpl76

    Jdpl76 Junior Member

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    I want to just ignore it but there is another party who does not ignore it if you know what I mean. What do I do about the quick shake on acceleration? It never shakes on idle. It happens at around 15 mph almost ever time. It can also happen at speeds of 50, 70 mph or really any speed when I am trying to just cruise and maintain a speed. If I put into power mode and accelerate aggressively I really don't feel it. It almost feels like a misfire but I have no CEL.
     
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  7. Mendel Leisk

    Mendel Leisk Witness Leader

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    Think so.

    You could start by removing the intake manifold, clean it out, and check the condition of the EGR passages. There's a large diameer intake port, and smaller tributaries, one per port. If those small passages are pretty much pristine it'll add weight to the leave it be argument.

    The EGR pipe between EGR valve and intake will likely be easy to do to, check the condition of it's interior.

    Note:

    1. You very likely can lift off the throttle body without removing it's coolant hoses. I wouldn't disconnect those hoses if not needed.
    2. If you do get to EGR cooler removal, and you don't want to do a full coolant drain-and-fill, maybe drain just a couple of quarts (from the radiator drain spigot, into a clean container. This should drop the coolant level below the EGR component, leaving the cooler more-or-less dry.
    3. The top two links in my signature are for third gen EGR cleaning, but may have some relevance. The second link has some ideas on the aforementioned two quart drain.

    Attached are Repair Manual excerpts for intake manifold and egr system. Telling: I just created the EGR excerpt this morning; so far it's never been needed.
     

    Attached Files:

    #7 Mendel Leisk, Aug 4, 2024
    Last edited: Aug 4, 2024
  8. Jdpl76

    Jdpl76 Junior Member

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    Thank you for your response and for the links to the manual. I won't be needing them after all. The car is in the shop as of this morning. I just gave up and I am not one to give up easily. I could not for the life of me get to the EGR valve or cooler on the Gen 4. It's a nightmare of a design but perfect for the dealer or shops. I could handle a Gen 3 all day. On the Gen 4 there is no room to get to the stud or nut without moving the high voltage inverter which 1/2" away from it blocking the studs or nuts. I removed several bolts from the inverter and it would budge a little but ultimately I couldn't get it to move and it's a $5000 part I don't want to mess with. So I was unable to install the new EGR valve which at first seemed like a easy task. I'm sure I could do the intake manifold but moving the inverter is beyond me.

    I put it all back together and took it to a shop. Once they give me a diagnosis I'll update.

    One thing is for sure. The engine is starving for air at light throttle.

    Thank you
     
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  9. Jdpl76

    Jdpl76 Junior Member

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    Well a Toyota shop specializing just called me and said they could only get it to shake once and it happened fast and they don't know anything. Suggested I take it to the dealer. $150 to have them tell me that.
     
  10. mjoo

    mjoo Senior Member

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    Was there a pool of hydrocarbons in the intake manifold underneath the throttle body?

    SM-A536V ?
     
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  11. Jdpl76

    Jdpl76 Junior Member

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    I haven't removed the intake manifold yet. But I will and let you know if I find anything

     
  12. Danno5060

    Danno5060 Active Member

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    Could it be a wheel bearing, CV Axle, or some other suspension component instead of the engine?