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Replaced head gasket. And then...

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Daniel Richard, Mar 20, 2020.

  1. Grit

    Grit Senior Member

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    Did you fill up anything around with water then?
     
  2. Daniel Richard

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    Not sure what your saying?
     
  3. tankyuong

    tankyuong Senior Member

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    Was the egr circuit cleaned before starting the car after head gasket removal?
     
  4. Daniel Richard

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    I cleaned it a couple thousand miles ago when I bought the car.
     
  5. IMkenNY

    IMkenNY Im just being nosy

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    An internal leaking egr cooler would allow coolant into every cylinder. To test this theory disconnect the coolant lines from the cooler and connect the lines to each other.

    It may be easier to look into intake manifold for coolant contamination where ultimately the egr flows into.
     
    #25 IMkenNY, Mar 21, 2020
    Last edited: Mar 21, 2020
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  6. Grit

    Grit Senior Member

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    Was thinking you filled something up with water to clean it and not all of the water evaporated or dried out and the water left over went into all cylinders.
     
  7. Daniel Richard

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    I was planning on doing this before I tear the engine down again. What I am going to do is bypass the EGR, EGR cooler, and heater core. Basically the water will only circulate between the engine and radiator. Then I can be for certain it is the head gasket.
     
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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Could you pressure test the EGR cooler?

    If you want to avoid spillage, drain a couple of liter of coolant (from the rad drain) into a clean container before pulling off off any hoses. This will avoid any spillage. Disconnect and plug all but one coolant pipes running into the EGR cooler, and apply pressure or vacuum to the remaining pipe, see if it holds.

    Pour the drained coolant back into the reservoir after all coolant lines are reconnected. Leave the bleed bolt (on hose atop the EGR cooler) open till coolant starts coming out, then quickly shut. Squeeze the main rad hoses as you're refilling might help. Coolant level will likely end up a little high, but driving (if and when) will drop it back to normal.
     
  9. ASRDogman

    ASRDogman Senior Member

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    Have you put a pressure tester on the coolant tank? That would be the easiest thing.
    If it doesn't hold pressure, you'll be able to see, or hear where it' s leaking.
    You could put the spark plugs out and look and listen to each cylinder for coolant...
     
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  10. Daniel Richard

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    It’s definitely coming through the head gasket. Last night I boroscoped the cylinder to check how much water was in each cylinder, and this morning I scoped it to compare, and there was more coolant in the cylinders this morning than last night.

    This evening I tore the engine down. Still baffled, but I will be milling down the block and head. Then putting in fel-pro gasket and beck/arnley head bolts. I am sure one of the three variables will fix the problem. I just wish I knew which one.

    If it doesn’t fix it I will have a cheap Prius for sale.
     
  11. TMR-JWAP

    TMR-JWAP Senior Member

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    Assuming you're taking it to a machine shop for that, at least they can check to see if something isn't straight first. I'm curious whether taking material off the deck and head surface will affect the engine.
    1. valve clearance will change between the valve head and pistons
    2. chamber volume at TDC will be smaller resulting in higher pressures
    3. centerlines will change between the cams and crankshaft, affecting the timing chain tensioner, I'd like to think it's capable of handling the extra slack.
    4. are there any accessories/brackets that bolt to both the head and the block? If so, those bolt hole locations will now be closer together and may not match the bracket.
    Do you have a copy of the Toyota repair manual? The engine mechanical section actually has a comment that if the head bolts are not removed in the correct order, damage to the head may result. They also specify that if either the head or block deck are out of tolerance for warpage, they are to be replaced. There's no spec listed for machining.
     
    #31 TMR-JWAP, Mar 21, 2020
    Last edited: Mar 21, 2020
  12. ASRDogman

    ASRDogman Senior Member

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    It is doubtful that block is warped. It's cast iron. The head is either cracked, or warped.
    Slight possibility that the gasket was bad.
    Or the holes the head bolts go into have/had water or dirt in them and you weren't able to get the
    bolts tightend tight enough, even though you were able to torque them.


     
  13. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Active Member

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    I believe the block is cast aluminum with iron cylinder liners
    https://www.motorreviewer.com/engine.php?engine_id=155

    Daniel Richard, did you use any type of sealant (Permatex, etc.) in addition to the HG? Did the progressive torquing sequence seem to go well? Like did it feel even and normal, with nothing binding or releasing as you finished it? Any chance one of the alignment pins caused a hang-up so the head could not be properly seated even though the torque sequence was completed? (just throwing a bunch of random thoughts at you to think about as you take it apart)

    If you had 1+2 leaking before, and now have 1-2-3-4 leaking, it seems that the problem is not a pre-existing condition, it must be something related to the repair.

    Did you follow videos or the manual when doing the work?
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    ^ That's making a lot of sense.
     
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  15. ASRDogman

    ASRDogman Senior Member

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    That's what I meant... the sleeves are cast iron. I was just thinking of the mating surfaces.
    Thanks for clarifying it. :)

     
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  16. Daniel Richard

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    I did not use sealant. It seemed to torque down normal.
     
  17. tankyuong

    tankyuong Senior Member

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    Engine swap probably next
     
  18. The Critic

    The Critic Resident Critic

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    You mentioned that aftermarket head bolts were used. Were these TTY bolts and did their length match the originals?

    Incorrect bolts providing the improper clamping force can cause all four cylinders to leak.
     
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