EGR Cooler Bottom Torx Stud Removal

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by PriusII&C, Apr 13, 2021.

  1. PriusII&C

    PriusII&C Member

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    I tried to remove my 2012 Prius EGR cooler today, but got stuck. After removing the bottom nut (it was actually pretty loose), I have difficulty in removing the torx stud. First the space is so limit that I can only rotate the ratchet around 30 degrees, so most of the time it cannot engage to the next tooth. In addition, the torx stud is very heavy, it makes me to wonder if I am tightening it. I rotate it counter-clock wise.

    Please let me know your experience.
     
  2. Raytheeagle

    Raytheeagle Senior Member

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    I just leave the stud there;).

    No need to remove it(y).
     
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  3. PriusII&C

    PriusII&C Member

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    Then do you need to remove the two torx studs connecting to the exhaust? In that case some people say it will be very difficult to put the cooler back. Is that true?
     
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  4. sLick415

    sLick415 Member

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    Yep, remove the 2 studs from the exhaust. Do not forget there is a gasket there like I did. It's not held in place by any clips so it'll slip right under once the coolers free from the exhaust. The tricky part when putting the cooler back is getting the gasket and the cooler properly aligned while getting the studs back in. But it's still much easier than trying reach under the cooler.
     
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  5. Raytheeagle

    Raytheeagle Senior Member

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    Remove the rear studs;).

    I've done the job about a dozen times and putting the cooler back on isn't near as difficult with the windshield wiper cowling off:).

    Just keep the below cooler bit off and you'll be fine the next round(y).
     
  6. AW82

    AW82 Member

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    Lots of people say to leave the lower nut on the exhaust attachment point off. Is that what you're referring to? Or are you saying remove the lower side stud on the side of the engine block after removing the cooler and then leave the stud out when you put the cooler back in?
     
  7. PriusII&C

    PriusII&C Member

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    Following @Raytheeagle and @sLick415 's advice, I removed the two rear studs, and removed the EGR circuit successfully. Thank you.

    Following @AW82 said, could the bottom torx stud be left removed? It looks to me that the assembly is mounted securely enough without it.
     
    #7 PriusII&C, Apr 13, 2021
    Last edited: Apr 13, 2021
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  8. PriusII&C

    PriusII&C Member

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    2012 Prius 113200 miles. Still can see light through cooler though. Hardly see any carbon deposit in the small EGR package.

    How important is it to take off the plastic cover of the valve? I tried with an impact screwdriver, but the screws wouldn't budge. It looks like I may damage the screws if trying harder.
     

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    #8 PriusII&C, Apr 13, 2021
    Last edited: Apr 13, 2021
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  9. sLick415

    sLick415 Member

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    You probably could nix the lower stud but you might hear a slight rattle. Maybe put some tape over the lower mounting point of the cooler.

    There should be 4 gaskets:
    - pipe to elbow
    - elbow to valve
    - valve to cooler
    - cooler to exhaust manifold

    You can get by without taking off the cover but it does allow you to push open the plunger so you can make sure to clean any buildup between the plunger and the valve body. I took mine off with a JIS screwdriver (#2 I think). Also a 2012 and I live 2 blocks from the beach.
     
    #9 sLick415, Apr 13, 2021
    Last edited: Apr 13, 2021
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    I took it out, mainly to be shut of it. It took upwards of 1/2 hour, due (as you noted) to the very limited swivel room with ratchet. Every twist I was stressing that I might round off the head, so went very cautiously. And yeah counterclockwise is the correct direction lol. Dissimilar metals is the likely culprit for the high resistance. It gradually gets easier, towards the end.

    once off, I reunited it with its nut and chucked it in my “spare Prius stuff box”.
     
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