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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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    I'll begin by adding my HUGE thanks to everyone who helped create the NutzAboutBolts videos. They are very VERY helpful!

    As an experienced test engineer, I tend to take note whenever my reality doesn't match the documentation, and I record what I've found.

    This thread will hopefully help any who are dealing with 2011 rather than other-year Prii... or perhaps what I see is just the normal variances seen due to timing and parts suppliers.

    I *WILL* get to that. But first, some crucial lessons learned today as I disassembled my 2011 Prius under the hood for the first time. Pictures will also follow. I'm just tired and need to zzzz but wanted to write this up while memories are fresh...

    COOLANT DRAINING
    • No need to go under the car at all, other than to place a low/wide bucket under the left end of the radiator.
    • As long as you're removing the intake manifold, once that's out of the way, look down and toward the driver's end of the bottom of the radiator.
    • You'll see a yellow tabbed screw cap. Loosen it and coolant drains straight down into your already-placed bucket. (Much faster if the overflow tank cap is removed ;) )j
    • With a few quarts of coolant drained, the only pipe that released some coolant for me was the lower back EGR cooler pipe. I clamped it off to avoid a mess. AFAIK that's the only clamp needed if you drain some coolant first.
    TOOLS
    • Yes you need an E8 (Torx External/Socket)... but it MUST be a shortie E8! There is a total of barely over 2 inches of working room in back for the back studs to be removed.
    • And it appears a shortie ratchet is also a necessity (unless there's a different solution I've not considered.)
    DISCOVERIES
    • As this was my first time opening it up (all prior work by dealer), imagine my surprise to find several cowl clips missing, and two of the nine cowl bolt heads broken off. No wonder it's been rattling.
    • (Anyone have experience convincing a dealer to take care of bolts THEY broke off?)
    • (I assume I get to do screw extraction and find some replacement/matching bolts)
     
  2. xliderider

    xliderider Senior Member

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    Wow, someone didn't use a torque wrench, or seriously over muscled those cowl nuts.

    Did you remove the lower mounting stud in the middle of the EGR cooler after struggling to get at the nut holding the EGR cooler on? I had such a hard time removing the nut that I decided to remove the stud and leave it off when reassembling everything.

    The other thing that gave me a hard time was removing all of the hoses that tend to get stuck on the fittings. A hose pick set really helps to "crack the seal" and that glycol coolant really helps to lubricate the hose to come off the rest of the way. Getting a good hold on the hoses was a challenge when working in the very tight quarters. A set of long nose hose pliers really helped in that area.

    Posted via the PriusChat mobile app.
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    I was under our sons Mazda CX-5 lately, and found many shield securing bolts and plastic fasteners missing, and he’s only had maybe two dealership interventions. :mad:

    Following your saga with interest. (y)
     
  4. MrPete

    MrPete Active Member

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    Gaaaah! A friend took me to auto parts store to get the correct E8.
    Within a minute of my return, it slipped off the torx pin and dropped into the bowels of the car :(
    My only clues: it fell from the top pin behind the cooler... and I heard metallic noises in its final motions before all was silent.

    Is it hopeless to go fishing with magnet-on-string?
    Is there a simple way to access appropriate under-vehicle parts?
    Do I just go get another E8?
    And what about Naomi?



    (That latter is a reference to an obscure kids' show on PBS :) )
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    It “may” be lying atop the engine underpanel.

    when I dropped the rearmost gasket (same loc), it hung up part way down. But it’s bulkier and lighter.
     
  6. xliderider

    xliderider Senior Member

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    Forgot to mention, another set of handy tools:

    An extendable magnetic pick-up tool, looks like an old school radio antenna with a magnet on the end.

    And a long, flexible, grabber tool. Has a thumb activated plunger on one end, and a small set of claws on the other. Used to retrieve stuff you can see, but can't quite reach.

    These two tools are indispensable for working on the Prius. The magnet can be used to hold parts in place while securing fasteners, or while removing fasteners, so good old gravity doesn't cause frustration when things inevitably fall.

    You can try getting under the car and, using your hand, pound lightly on the engine undercover to see if you can hear the tool bouncing on it. Then you can try to bounce it towards an edge where you can retrieve it, or worst case scenario, drop the cover down to get it.

    Posted via the PriusChat mobile app.
     
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  7. CR94

    CR94 Senior Member

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    The most important plastic pushpin, the one that holds the oil-change flap closed, was missing when my CPO Prius was delivered. I complained at my first "free" oil change, and they provided another one.
     
  8. MrPete

    MrPete Active Member

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    Great pick-er-upper ideas. Thanks! I'm thinking I need a little webcam-on-a-stick to look around down there. :)

    In any case... bought another e8, finished removing the final bits... oh boy does this poor car NEED some EGR cooler TLC!

    Water simply does not flow through at all, it is so clogged. Cleanup on aisle 29 has begun..
     
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  9. MrPete

    MrPete Active Member

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    Update to the OP tools section:
     
  10. Raytheeagle

    Raytheeagle Senior Member

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    There are inexpensive WiFi borescopes out there:).

    They make a good addition to the tool chest;).

    Good luck with reassembly(y).
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    Concentrated hot tap water solution of powdered Oxi-Clean Versatile Stain Remover worked for me. Takes some patience: cork one end and fill with solution, let bubble about an hour, rinse and repeat. Four or five sessions should get it like new.

    With near-total clogging you’ll likel need some wire prodding as well, to allow the solution to penetrate. It needs to be quite a thin wire; the passages are narrow as heck.
     
  12. Tombukt2

    Tombukt2 Senior Member

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  13. MrPete

    MrPete Active Member

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    DISASSEMBLY and NOTES ON TWEAKS to NutzAboutBolts Videos

    A starting point: clean but unhappy 2011 Prius Gen3

    [​IMG]


    General Comments on sequence and timing of removals/cleaning:
    • The EGR cooler takes much longer to clean than any other part. I wouldn't bother cleaning anything else until you've got the EGR cooler in its first round of whatever soaking is needed. There will be plenty of time for cleaning everything else.
    • 2011 Prius III: there's only about 2 inches of headroom between the cowl and the top of the igniter/spark plug access. [H/T @ChapmanF: that's true for drive-on-the-right. Drive-on-the-left have a different wiper setup and smaller cowl!]
      • I waited until after the IM was removed to remove my cowl. Just curious about how far I could get while leaving it in place.
      • IM removal is easy without removing the cowl.
      • EGR/cooler removal? Fuggedaboutit. You must remove the cowl to get that done, at least in the USA... maybe on a lift? I don't happen to have one...
    Cowl Removal (NAB Spark Plugs Remove and Install video)
    • 3:45-4:50 Clip removal. A trick I learned and expanded on from comments in a video on HV battery removal: almost every clip of that type can be cleanly and easily released using a 10mm socket or equivalent if no room for a socket! (10mm ratchet wrench, combo wrench, etc.)
    [​IMG]
    Intake Manifold Removal (NAB IM Cleaning video)
    • 2:53 NAB lifts off the air intake after removing two 10mm bolts. Mine is not that simple: there's a wire bundle zip-tied to a post on the (driver-right) left end of the intake.
    [​IMG]
    • (As @Mendel Leisk has noted, there's no need to disconnect the coolant hoses to the throttle body. It easily moves out of the way for removing the IM and/or EGR/Cooler.)
    • 9:10 there's a bolt with a wire bundle right next to the head. I couldn't even fit a 10mm combination wrench in there, but a box wrench was fine.
    [​IMG]
    • 10:50 on mine, the EGR pipe metal gasket has strong spring clips holding it in place. Only a small amount of care is needed to avoid dropping it.
      (Note from EGR Pipe Cleaning video, 9:10 -- the gasket actually clips to the EGR, not the EGR pipe! So please ignore that the gasket is attached to the pipe here)
    [​IMG]
    • 12:11 the clip under the large cable bundle is tricky to release. It's actually squeezed from the sides, underneath, accessible with a screwdriver or two from the windshield side of the engine.
    [​IMG]
    • 12:15 several clips are squeezed from the back side. (As described above, use the same 10mm socket/ratchet/combo wrench trick to easily remove.)
    [​IMG]
    • My Intake Manifold looks pretty bad. Is that a blob of junk just sitting there? Yeesh.
    [​IMG]

    NAB EGR / EGR Cooler video
    • With the IM removed, the coolant drain is easily visible from above. Time to remove a few quarts of coolant before we continue.
    [​IMG]
    • 1:00 I don't need to clamp the coolant hoses. Saves a bunch of hassle and mess. Thanks, @Mendel Leisk! :)
    • 6:20 and 12:40 There's a metal gasket between the EGR Cooler and the Exhaust Manifold. Fortunately, there's enough visible, I was able to use some duct tape to hold it in place, thus avoiding any concerns about loosing it while removing the EGR cooler.
    [​IMG]

    Result of Disassembly: My EGR Cooler has NO flow at all!

    I am soooo glad to be doing this procedure. My EGR cooler was 100% clogged. I could pour water in one end and let it sit for an hour with no leakage.

    Cleaning steps so far (about 15 hours so far including an overnight pause):
    • Initial hot water rinse
    • OxiClean for a short while, mostly to get the bulk surface gunk off
    • Power wash with low pressure (wobbler) spray. What a mess!
    • Several OxiClean soak-until-no-more-bubbles at each end. (Result: both ends look nice and shiny, and a few carbon chips came out, but still no water would go through!)

    • Power wash again. More gunk out.
    • Power wash with a 0 degree needle spray. Suddenly, water's coming out the other end! Water at the end of the tunnel so to speak.
    • (Current) Realizing I want all channels open, I took a two quart pyrex measuring bowl, dunked one half of the cooler in it, mixed up oxiclean and poured in until the bowl was full. I'll let that soak, then flip and do the other end. This might not be enough to get the center but it should come close.
      (Meanwhile, I'll hunt down some good stoppers, and a spare bicycle tire spoke, and see if I can soak the entire insides.
     
    #13 MrPete, May 17, 2022
    Last edited: May 17, 2022
  14. xliderider

    xliderider Senior Member

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    Great, detailed, write-up.

    Even with a wire, because of the way the cooler opening is offset slightly at an angle, due to the openings being smaller than the cross section of the cooler, you will have a hard time getting the passages on the edges clear, unless you can find a wire that is somewhat flexible. Work at it from both ends.

    Posted via the PriusChat mobile app.
     
  15. Tombukt2

    Tombukt2 Senior Member

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    I can't wait to send the two or three that I have over to my local machine shop and see what happens when they tank them and clean them and whatever it is they do like everything I send them over there when I do or used to would come back whistle silver metal clean whatever the color of the metal was gold silver blue would come back with nothing on nothing I realize this is a miniature radiator so you can't be blasting on it and stuff or it'll be compromised and then you have a mess
     
  16. Tombukt2

    Tombukt2 Senior Member

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    I wonder if it was made a little larger not a whole lot just a wee bit
     
  17. Mendel Leisk

    Mendel Leisk Senior Member

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    Excellent write up, all the pitfalls and gotchas. (y)(y)(y)

    IIRC @Raytheeagle did forego the cowl removal, one time, vowed never again...

    Your cooler travails are a lot tougher than mine; I was on it at 70K kms. Multi-method approach sounds good.

    I found a cable TV coax cable wire, the thinner kind, not more robust ones, was about the right gauge. Even then it complained/balked, all the way through. Deburring the tip helps, reduces the snagging.
     
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  18. MrPete

    MrPete Active Member

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    Looks like the 2 quart OxiClean bath loosened it up enough so that a needle power wash spray could cut through. Results ASAP.

    I'm about to go out and collect the gaskets, PCV valve, etc ordered at the dealership. May do plugs while I have it open. It was 70k miles ago at 130k... hmmm
     
  19. MrPete

    MrPete Active Member

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    Oh, a key question: I blasted the EGR itself with water. Was that a horrific thing to do?
     
  20. ChapmanF

    ChapmanF Senior Member

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    It depends on the country. Where they drive on the left side of the roads, those Gen 3 Prii don't have the big double-jointed windshield wiper making the cowl jut so far over the engine, and the spark plugs are easy peasy.

    Where roads are driven on the right, as in the US, no spark plugs for you without taking the cowl out. The igniters don't come even nearly out of the plug tubes before their tops bonk into the cowl.

    As far as injectors, I don't think the cowl has much influence over access to those.
     
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