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How to clean clogged EGR cooler?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by anonymous, Jul 22, 2018.

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  1. cnc97

    cnc97 Senior Member

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    I zoomed in on it. Dawn Professional Power Dissolver. I’d never heard of it before today.
     
  2. SFO

    SFO Senior Member

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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Judging from the above PDF, PH is 13, about the same as oven cleaner. Oxi-Clean is 11, worked for me. But yeah if it's tough, higher miles you could give it a try. Be really careful with it though: gloves, eye protection, wear old clothes, rubber apron and so on.
     
  4. ASRDogman

    ASRDogman Senior Member

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    Okay, thanks. But I'm super happy with the ease of oven cleaner. :)
    But the pressure washing is calling to me.......

     
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  5. mikey_t

    mikey_t Active Member

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    I find this really interesting:

    "mostly powdered carbons easily blown by compressed air"

    I wonder what causes the difference.
     
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  6. CR94

    CR94 Senior Member

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    Is it acquiring its exhaust gas post-converter, like the 4th-generation Prius does (as I understand)?
     
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  7. Mendel Leisk

    Mendel Leisk Senior Member

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    ^Very good point; that could well be the difference. Some 4th gen'r (preferably with at least 50K miles) should get off their duff, check and post a pic of the EGR pipe, the piece between valve and intake manifold.
     
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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Considering the revised 4th gen EGR intake location (downstream of the Cat, as opposed to 3rd gen's in the exhaust manifold), and the more-or-less doubling of the EGR cross-sectional area, it's readily apparent the Toyota engineers had alarm bells ringing. EGR revision is even noted in a white paper on the 4th gen Prius (which I can't find at the moment).

    Meanwhile, for 3rd gen owners, they don't want to know. They pay lip-service, but too-little-too-late.
     
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  9. anonymous

    anonymous Member

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    Here is what the cooler looked like 32.5k miles after last cleaning
    IMG_7589.JPG
    Actual flow was worse than it appears; barely let any light through and was almost clogged again.

    Cleaned again, initially with brake cleaner then rest with pressure washer. Did a good job but didn't clear all passages, so it probably won't last as long (although now with new valve stem seals maybe it won't dirty up so quickly)
    IMG_7829 (1).JPG
     
  10. ASRDogman

    ASRDogman Senior Member

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    So you believe the oil leaking is through the valve guide seals?
    I replace a lot of mid 80's Mercedes valve guide seals. Some type of defect.
    Made lot's of money from those jobs! Easy and fast! :)

    I think it's more the seals than the rings. I haven't seen any photos or video of the rings clogged up.
    I'm not saying that they are not doing that, I just have not seen any.

    It would seem there would be more cylinder failures if the rings clogged, it would seize.

     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    Holy smoke! That's quite well along. I'm gonna make a note of that, appreciate the datum. Did you have an oil catch can?

    Send an Xmas greeting card to Toyota, with that "before" snapshot on the front.
     
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  12. Bbonez

    Bbonez Member

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    I'm going to pull my cooler and clean it out soon, I like the idea of using a pressure washer as i have access to one with a diesel burner to heat the water. I was planning on using hot water and some of this degreaser:

    20191118_102954.jpg

    Is there anything we need to be careful with when hitting the cooler with a high pressure hot water/degreaser combo?
     
  13. cnc97

    cnc97 Senior Member

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    Why do I have the urge to pull the EGR valve on mine that has 18k since cleaning just to take a look? Seeing this makes me very curious to see how mine is doing.
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    And it's so much easier the second time 'round...
     
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  15. Raytheeagle

    Raytheeagle Senior Member

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    Particularly if the lower nut under the cooler has been left off;).

    I did our 2010’s circuit cleanse twice and the second time at a 50k miles interval:).

    Thought that was appropriate for future changes(y).
     
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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    With @anonymous' pic it looks like the rightmost portion was 100% clogged, maybe since last time? That mighta accelerating the clogging of the rest??

    Hey, I'm with @cnc97...
     
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  17. Raytheeagle

    Raytheeagle Senior Member

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    Channeled flow leads to issues as there is less area to distribute the load:cool:.

    But a frequent cleanse is required (y).
     
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  18. cnc97

    cnc97 Senior Member

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    I’m thinking pull the EGR valve, undo the exhaust tube, and hose it down with brake cleaner. Then let it air dry. If Sunday is nice here like they say, I’m going that route.
     
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  19. Eddie25

    Eddie25 Active Member

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    So you're gonna try to clean it while still mounted? It would be great to not have to pull the coolant hoses. I would still do the wire on the drill thing, I would think that would give you the most bang for your buck. Is it possible to move the exhaust pipe out of the way once it's disconnected?
     
  20. cnc97

    cnc97 Senior Member

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    My engine has only 18k or so since last cleaning. If I find anything pulling the valve, I’ll decide how to proceed.
     
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