2011 IM+EGR Coolant Cleanup Saga - With updated details

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by MrPete, May 16, 2022.

  1. MrPete

    MrPete Active Member

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    Updated my post from 6pm above. No more codes. Starting to have some hope that I've saved this engine from serious trouble. Yes, still need to do gaskets. Yes, most likely it burns some oil, but perhaps a bit less? We'll see.
     
  2. Mendel Leisk

    Mendel Leisk Witness Leader

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    I believe you drained a couple of quarts (approx), then added it back to the reservoir? Did you open the vent while refilling? It's atop the EGR cooler*, incorporated into a plastic gizmo (believe it's a coolant temp sensor?), a white, knurled plastic cap with a spigot on the side.

    If you loosen that off while filling air can escape as you fill. You could try loosening it now, see what happens. I suspect you'd get some air out, then coolant. At that point you want to close it. You can push a transparent hose onto the spigot, both to direct the coolant spillage and make it easier to see when it transitions from air to coolant.

    * Addendum: should be, for model year 2011. If I'm not mistaken, the coolant air vent was nixed in 2012 model year. If you DON'T have the valve, pulling off a topmost coolant hose temporarily would accomplish the same vent function.
     
    #62 Mendel Leisk, May 20, 2022
    Last edited: May 20, 2022
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  3. MrPete

    MrPete Active Member

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    Sigh. P0441 is baaaack. Additional measures and symptoms:

    Purge Flow Monitor tests (MID $3f, TID $c9-$d7
    - Some are good (all but $d4 and $d7) ranging from 0.33 ($c9) , many ~1.67, some 2.4
    - Two are bad: $d4 at -0.308 and $d7 at -0.484 kPa

    The engine is often idling around 2000rpm (Stage 3 -- from Hybrid Assistant app) for no apparent reason

    QUESTION: Is there anything to be learned from the code or Purge Flow Monitors? Or do I just need to tear into it all and recheck everything?
     
  4. Mendel Leisk

    Mendel Leisk Witness Leader

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    With all this coming on the heels of your “intervention”, I’d suspect something not reconnected correctly.
     
  5. MrPete

    MrPete Active Member

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    (@Mendel on the coolant valve: mine has a black tube with nothing on the end. I suspect it has no valve, since I see nothing to open. I've never seen a photo of the valve, although I think you described it as a white knurled cap?)

    Yes, I suppose it's likely something is misconnected with respect to air. Need to search the various PDF's for a diagram showing air flows...
     
  6. Mendel Leisk

    Mendel Leisk Witness Leader

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    The knurled cap on that valve is white, atop the black plastic portion. It has wires running to it (thermostat). Ok, sounds like no valve. You can stil try pulling off the hose at that component: gently, and push it back on if/when you get coolant coming out.
     
  7. MrPete

    MrPete Active Member

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    QUESTION: Is it possible that my code could be due to too-long hoses in my new OCC setup? I cut them extra long to give flexibility in final placement. They are not kinked, but most definitely longer than normal (ie about a meter long.) There is enough that the hoses circle back (gently so as not to kink).
     
  8. Mendel Leisk

    Mendel Leisk Witness Leader

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    Don't think the extra length would cause a code. And a vacuum leak probably wouldn't either. When I first installed an OCC I inadvertantly left the drain tap open, essentially a gross vacuum leak. It sounded odd, on a drive round the block, but no code.
     
  9. burebista

    burebista Active Member

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    You can see it in this thread. Last pictures.
     
  10. Mendel Leisk

    Mendel Leisk Witness Leader

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    Snapped pics of the valve. Suspect now it's only on model year 2010. :(

    517AE8BE-50B0-45F1-BFBB-6102156254D1.jpeg DAF42FEC-D4EF-4BD7-B212-76FA01BF646F.jpeg
     
  11. MrPete

    MrPete Active Member

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    So mine is exactly the same, without the white bit ;)

    My coolant is now down to "full".

    My only other coolant question is perhaps actually a water pump question. Until this week I was unaware of the apparently serious impending-water-pump-failure issue.
    • How will I know if water pump fails? Is there a code?
    • Is it expected that coolant ought to get pretty close to 200F or so?
     
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  12. ChapmanF

    ChapmanF Senior Member

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    Cars in years that we think have the white valve in that tee, and cars in years we don't think have the white valve in the tee, list the same Toyota part number for the tee.

    So somewhere along the line, they just changed the way that tee comes.
     
  13. Mendel Leisk

    Mendel Leisk Witness Leader

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    Prophylactic replacement of water pump by 150k has been advocated here.
     
  14. CR94

    CR94 Senior Member

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    My 2011 does not have the vent valve. That might've been a mid-year change.
     
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  15. xliderider

    xliderider Senior Member

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    Our 2011 doesn't have the vent valve either.

    I did not do anything special like remove a hose from the fitting till coolant started to come out when filling the coolant after draining it out. Just monitored the coolant level and topped up when needed.

    Posted via the PriusChat mobile app.
     
  16. ASRDogman

    ASRDogman Senior Member

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    I just replaced the empeller at 266710 miles, March 22nd. It was the same as the original one.
    I wasn't going to replace it because the original one still turned freely and not swelled or cracked.
    But I dropped the pump as I was setting it back it and it broke the ring on the blades. :(:mad:
    So I put the new one in. $40? I think it was.

    272??? miles and no problem

     
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  17. xliderider

    xliderider Senior Member

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    I purchased a new water pump and thermostat/housing and was going to proactively replace them when I changed the coolant at 124K miles, along with cleaning EGR cooler and intake manifold.

    However, I decided to save the water pump and thermostat/housing for later, when there actually is a problem with either. With any luck, it won't be for a while. I might change them out if they make it to the next coolant replacement interval.

    Posted via the PriusChat mobile app.
     
    #77 xliderider, May 21, 2022
    Last edited: May 21, 2022
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  18. MrPete

    MrPete Active Member

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    GREAT news. In several minutes of driving around today, P0441 lit up twice. I bit the bullet and started pulling it apart again.

    Fortunately, I did not have to go far. @Mendel Leisk was correct of course. It was the electrical connection to the Vacuum Switching Valve.**

    I had not fully attached the electric connector and it came off while I was still assembling other bits. SMH. This time it's clicked fully in place.

    No more P0441 code. And Purge Flow Monitor tests (MID $3f, TID $d4 and $d7 that were bad, are now normal :) )

    Now to wait for the gaskets to arrive Monday, and I can finish this completely! Still a week to go before our 4000+ mile drive to nature photo destinations along the US-Mexico border and more. (I've also ordered a dual-lens USB endoscope with magnet and hook attachments. Should let me examine cylinders/pistons, and perhaps even retrieve my tools that dropped into the bowels of the engine compartment :) )

    ** The VSV has two hoses at right angles, and an electric connection. Hoses connect to EGR (cooler) and to the front of the Intake Manifold. It's visible in the NAB EGR cleaning video at around 16:00)

    PS My prius was built August 2011 and has no coolant valve above the EGR. It's the "early" Gen3 for certain parts choices. ("Late" began in Nov 2011.)
     
  19. MrPete

    MrPete Active Member

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    Just found my best-ever source of info on at least some Toyota-specific codes. This is direct from Toyota. Their explanation of p0441 is wonderful -- and leads directly to the likely answer if one has been messing in the engine compartment ;)
    https://parts.olathetoyota.com/toyota-trouble-codes
     
  20. Paul E. Highway

    Paul E. Highway Active Member

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    I replaced water pump on my 2010 at 156,888 miles just for peace of mind. And it's always warm/hot here!
     
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