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EGR cooler nut & studs are frozen

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by bbrages, Jun 16, 2024.

  1. bbrages

    bbrages Junior Member

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    2005 Prius
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    Started in on a big Prius service on Saturday. I replaced the water pump (it looked fine) and took off intake manifold (quite a bit of carbon). On to the EGR cooler, ran into a problem. The lower nut on the flange attaching to the exhaust manifold was too rusty. Socket just rounded on it, didn't turn it.

    On the upper stud, I tried to remove the stud but just sheared off the torx tip of the stud. Did the same thing on the lower stud.

    The other studs came out, even the really hard to get to one. Well, I almost got that one out, then I dropped the ratchet into the engine bay and the E8 torx socket got lost in there somewhere. Sigh.

    I ordered a new EGR cooler off of eBay because I think I might have to cut this one up a bit in order to get it off without damaging the EGR fitting from the exhaust manifold.

    So... hmm. I guess I will try clamping on a Vise-Grip to the rusty nut, if I can get one on there. Then, I think I might try sawing through the EGR cooler and just leaving the flange on there. Then I should have access to drill or Dremel on it to cut off the bottom stud.
     
    #1 bbrages, Jun 16, 2024
  2. Tombukt2

    Tombukt2 Senior Member

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    Mini pin torch .
     
    #2 Tombukt2, Jun 16, 2024
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    South Main Auto YouTube mechanic is in upstate New York, and a lot of his work, especially of late, is replacement of rusted out sub-frames. He just stoicly soldiers on, using impact wrenches/hammers, torch, chisels, what have you. Often needs to hammer sockets to get them on rust-swollen nuts/bolts. North America’s gotta address this love affair with road salt.

    was your engine under shield intact/complete?

    another good reason to at least get started on EGR work sooner than later. Even if it’s just to back out fasteners, leave the cooler lower nut AND stud off permanently, and for the rest: butter them up with anti-seize and reinstall.
     
    #3 Mendel Leisk, Jun 16, 2024
  4. bbrages

    bbrages Junior Member

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    2005 Prius
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    I ended up finding my E8 and was able to remove the hard-to-get-to stud. Then I used a reciprocating saw (sawzall) to cut off the bottom stud attaching the EGR cooler to the pipe from the manifold. Finally got it out! Did a bit of damage to the flange from the EGR pipe, but I think that it's going to work all right. At least this way I don't have to clean the old EGR cooler. :)

    My engine under shield is intact but there are a lot of rusty fasteners on the engine. The car came from Indianapolis. Body is in decent shape but the wheels are a bit corroded.
     
    #4 bbrages, Jun 18, 2024
    Mendel Leisk likes this.
  5. bbrages

    bbrages Junior Member

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    2005 Prius
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    Got everything cleaned up and put it together last night. I have been noticing some surging on the highway at low throttle (the first half of the "Hybrid System Indicator"). Normally, the car would be running on only the battery at that point. I'm hoping/guessing that it is related to having the car inoperable with the 12v disconnected for a couple of weeks and that it will learn itself back to normal operation.

    Otherwise, no check engine lights and it seems like the transition from EV to gas is a little bit smoother.
     
    #5 bbrages, Jun 27, 2024 at 11:59 AM
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