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Remove cylinder head sub assembly

Discussion in 'Gen 3 Prius Technical Discussion' started by RyanFlorida, Apr 20, 2018.

  1. RyanFlorida

    RyanFlorida Member

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    I am working on replacing the head gasket in my 2010 Prius 2ZR engine. I am down to the Cylider Head Sub Assembly but cannot get it off! Has anyone done this before, can anyone give me any tips? I removed all of the head bolts, engine mount, timing cover bolts, and anything else I could find that is near the head. I can get a screwdriver gently under one corner and raise it about 1/4 inch and cannot get it to move past that. I removed the nuts from the exhaust manifold but could not get the entire assembly off, when I move the head assembly it is moving freely from the exhaust manifold. Pic is from before I removed the head bolts.
     

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  2. bisco

    bisco cookie crumbler

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    are you using the service manual?
     
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  3. GrGramps

    GrGramps Active Member

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    Never worked on one of these engines, but I wonder if your problem is related to the timing chain and camshaft sprocket??
     
  4. RyanFlorida

    RyanFlorida Member

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    bisco, I do have the manual, however I could not get the exhaust manifold off. There are two bolts holding it to the cat which I cannot budge out of place. I was able to remove all nuts from the rear exhaust port on the head. Pic below shows nuts on exhaust port, the nuts I can get off, the posts they screw on to are removable but I can't get those off either. 20180420_162925.jpg
    GrGramps, timing chain and sprockets are already removed, that was an adventure in itself!

    20180419_181227.jpg
    Must set chain to top dead center, orange links to those marks you see in the pic, then below the camshaft notch will line up to the 0 mark. Took about 30 minutes to get it in perfect placement, had to spin the cam shaft at least 30 revolutions to get the chain perfect.
    20180419_181236.jpg
     
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  5. bisco

    bisco cookie crumbler

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    check @danlatu 's threads, not sure if he details it or not.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    @danlatu maybe will have ideas. As we have invoked his name, when he comes online hopefully will notice this, have ideas.
     
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  7. tpenny67

    tpenny67 Active Member

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    Thanks for posting the pics! It's the first shot I've seen under the valve cover of the gen3

    Posted via the PriusChat mobile app.
     
  8. IMkenNY

    IMkenNY Im just being nosy

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    I would think complete removal of the timing chain cover would be the norm.
    On other four cylinder engines I have had good luck leaving the exhaust manifold attached to the head and i have disconnected the exhaust at the flex connection but I cant speak for this 3er generation Prius.
     
    #8 IMkenNY, Apr 21, 2018
    Last edited: Apr 21, 2018
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  9. Raytheeagle

    Raytheeagle Senior Member

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    If attempting this work while the block is in the Prius, @leeb18c muggt had some advice:).

    That’s how he did his head gasket replacement ;).

    Good luck with your project and keep us posted (y).
     
  10. RyanFlorida

    RyanFlorida Member

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    I think that's the best advice, just remove the timing cover. After further inspection I believe there are two bolts that hold on the front timing guide, one in the lower block and one in the header assembly which the part I still cannot remove.

    I have been trying to find how to remove the camshaft pulley, anyone know how to do that? I should be able to get the timing cover off tomorrow but that camshaft pulley is still in the way :rolleyes:
     
  11. danlatu

    danlatu Senior Member

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    You can use the two bolts that hold the ac unit to remove the pulley. Use a pulley removal tool or bearing removal tool. I would remove all the head studs and leave the manifold alone, you have to pull the timing chain cover, engine mount, timing chain guides, This engine sucks to work on.

    Screen Shot 2018-04-22 at 2.46.06 AM.png IMG_0270.JPG
     
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  12. RyanFlorida

    RyanFlorida Member

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    Awesome, thanks for that. So how do I get the crankshaft bolt out? Is it reverse thread?
     
  13. farmecologist

    farmecologist Senior Member

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    Wow good stuff. (y) You are way, way more adventuresome than I am! Bravo sir!
     
  14. RyanFlorida

    RyanFlorida Member

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    Got the head out! Thanks for all the tips!

    I'll post more pics and a write up once it's all back together and working!

    Hoping to make a timelapse video when putting it back together
     
  15. RyanFlorida

    RyanFlorida Member

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    Bunch of pics:
    1. Top of pistons and exhaust manifold
    20180422_153907.jpg
    2. Timing chain at front of pic, left side of vehicle
    20180422_153925.jpg
    3. Very bad build up on piston 2, I believe its number 2, second from the right
    20180422_153952.jpg
    4. All bad carbon build up on piston heads
    20180422_154030.jpg
    5. Intake valves ok, exhaust valves have a lot of buildup probably from sucking coolant
    20180422_154740.jpg
    6. All clean! New valve seals. I removed all of the valves and cleaned them up
    20180422_183018.jpg
    7. Close up, so clean, so nice
    20180422_183027.jpg
     
  16. RyanFlorida

    RyanFlorida Member

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    I was able to remove the crankshaft bolt by tightening the removed ac mount bolts into the crankshaft pulley and using a breaker on the crankshaft bolt. Bolt is NOT reverse thread. Lefty loosy! Doing this put a few scrapes into the block. To me, they're scars, battle wounds, it adds character.
     
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  17. douglasjre

    douglasjre Senior Member

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    I'm just south of you in Lakeland doing the same job now. It looks like your leak was into cylinder 2. Mine was into cylinder 1. IMG_20180417_182604.jpg IMG_20180417_182549.jpg
     
  18. Gypsy62

    Gypsy62 Junior Member

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    Newbie '05 owner (Pro soob mechanic).
    Suggestion:
    Anytime I pull a head on any vehicle, I use "Aircraft Aluminum Spray Cleaner" to remove any carbon build-up on the tops of pistons. Presumably, you had the head tank-cleaned (and maybe magnafluxed, valve-seats spun, etc) at a machine shop before installing the fresh valve stem seals (& other fresh valvetrain components?).
    I refuse to mount a freshened head & gasket above ugly dirty pistons. 5 minutes with spray cleaner and they look new. Performance benefits as well. Effective but toxic stuff; use a respirator & heavy rubber gloves while ragging clean.
     
    #18 Gypsy62, Apr 22, 2018
    Last edited by a moderator: Apr 23, 2018
  19. RyanFlorida

    RyanFlorida Member

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    We have some nice weather to be doing this right now! I've been doing mine in the driveway.

    How many miles on yours? Did you clean those piston heads, or was that how they were? Mine had a lot of bad build up.

    Gypsy62, I cleaned my piston heads with carb cleaner, they came pretty clean. I'm sure aircraft aluminum cleaner would shine them up nicely. If I was doing this job on a sports car or a larger engine I would get them the cleanest I could, but this is a cheap car, I'm not going to put too much into this.
     
  20. douglasjre

    douglasjre Senior Member

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    No cleaning on my part. I was a mechanic years ago and never did clean anything. We had cleaning people for that.

    Mine is in the garage. 210k miles and it's one of two Prius I own. I convinced 7 of my friends to get Prius'. We have gotten quite good at servicing them and this is the first head gasket job among our collective Prii. Send you a picture with my number. Buzz me if you run into any roadblocks. We might need to share ideas.
    Doug
     
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