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3rd generation head gasket project

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by IMkenNY, Jun 23, 2019.

  1. IMkenNY

    IMkenNY Im just being nosy

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    The glacier has receded here in Tropical Buffalo NY and I found a warm weather project for sale on Craigslist.
    I picked up a 198,000 mile 2012 Prius with a blown head gasket for $1500.00

    The cargo area was filling up with all of the engine parts after I dismantled the engine
    IMG_0762.JPG

    I was happy to see the stiffening crankcase assembly was easily removed with the block still attached to the transaxle because a connecting rod was unable to handle the forces that were exerted trying to compress coolant.
    As you can see from the picture of the top connecting rod, it is unwise to put off a head gasket replacement. Fortunately no other damage was done to the Crankshaft or cylinder. IMG_0763.JPG IMG_0764.JPG
     
    #1 IMkenNY, Jun 23, 2019
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  2. Mendel Leisk

    Mendel Leisk Senior Member

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    That first picture has my cleanliness OCD meter ringing off the wall, lol.

    Are you going to do the piston/ring upgrade? Info in the attached TSB.
     

    Attached Files:

    #2 Mendel Leisk, Jun 23, 2019
    Last edited: Jun 23, 2019
  3. ChapmanF

    ChapmanF Senior Member

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    Interesting. Do you plan on also reinstalling the lower crankcase with the transaxle in place? What are your plans for the rear main seal?
     
    #3 ChapmanF, Jun 23, 2019
  4. IMkenNY

    IMkenNY Im just being nosy

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    I only removed the damaged piston in cylinder 3 and was impressed with the current state of the compression, oil control rings & spacer so I decided to not replace them.
     
    #4 IMkenNY, Jun 23, 2019
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  5. Dave Hanson

    Dave Hanson Member

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    I'd be a little leery of reusing the block, saw recently on here where someone put in a new head gasket and the block cracked shortly thereafter. The bend on that rod tells me that there was tremendous amount of pressure exserted and it might be time to do a low mileage 2016 and up engine retrofit. I'd do some more checking on here and ask for advice from someone like ragfit or cnc97, before I'd spend to much money on this engine. Also do you know if previous owner used any cooling system sealer, because that can create problems with heater core and radiator down the road. p.s. also need to check into egr cooler cleaning.
     
    #5 Dave Hanson, Jun 23, 2019
  6. IMkenNY

    IMkenNY Im just being nosy

    Joined:
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    2012 Prius
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    Four Touring
    I installed the new connecting rod and lower block yesterday. I was very careful to lift the lower block straight up and I am fairly confident rear seal is properly seated.

    I plan on testing the rear and front seals after installing the timing cover by overfilling the oil by three quarts before I install manifolds etc. (I will be draining out extra oil before starting the motor)

    It should be noted that once the timing cover is removed the lower block assembly is easily removed with the oil pan attached by simply removing the eleven 12 mm bolts, 6 lower block to transaxle bolts and three AC compressor bolts. The front and rear motor mounts stay attached to the transaxle.
     
    #6 IMkenNY, Jun 23, 2019
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  7. The Critic

    The Critic Resident Critic

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    If you need a rear main seal I still have the new one leftover from my overhaul gasket kit. I would be happy to send it to you at no charge.
     
    #7 The Critic, Jun 23, 2019
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