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Another noob headgasket question...

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by Garra671, Dec 1, 2020.

  1. Garra671

    Garra671 Junior Member

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    Hey guys. Sorry for all the noob headgasket questions. I just don’t wanna end up doing it twice... 2012 Prius V


    Do you guys think a new headgasket will seal properly with this small bit of residue left?


    Everywhere else on the head seems to be pretty smooth and no catching with fingernail.


    I ordered a roloc wheel, that’s good for aluminum heads. But it won’t be here another 2 days. So I’m trying to avoid waiting if I don’t need too.


     
  2. cnc97

    cnc97 Senior Member

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    Get a long file. Lay it flat across the block and/or head. Drag it from one end to the other, the full length of the block. Two or three times will take care of that.
     
  3. Garra671

    Garra671 Junior Member

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    Sorry. But no way no how. Am I going to use a file on aluminum.
    I don’t trust myself too not dig it in. Or catch an edge.
     
  4. cnc97

    cnc97 Senior Member

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    The roloc disk you are waiting for is way more harmful then draw filing the head and block. The other option is to get some 1000 or 1500 grit sand paper and glue it abrasive side out to a piece of glass, and lightly sand the surface clean.
     
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  5. Garra671

    Garra671 Junior Member

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    @cnc97 Well... I really think I did it now... I used the 3m white bristle disc. Which is supposed to be safe for aluminum... and maybe it is...


    but upon trying it just for a couple of seconds...... this was my result.


    Is my cylinder block going too need to be resurfaced now....?

    my fingernails don’t catch on the scratches. It feels like a slight roughness. 4DAECFA4-AF50-46FC-A26B-CE9B64FBAD46.jpeg
     
  6. cnc97

    cnc97 Senior Member

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    1000 or 1500 grit wet/dry sandpaper and a piece of glass or finished plywood. Make sure the glass/wood can reach all the way across the block. That is the best and safest way to clean up the block or bottom of the head.


    There is a standard for surface finish that Toyota recommends the block be finished to. Short of removing the block and having it surfaced, light sanding until the texture is all the same is the way to go. It should only take a minute or two of light sanding to get you where you need to be.
     
  7. cnc97

    cnc97 Senior Member

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    The important thing is this, the gasket can and will seal some surface imperfections. But the smoother and flatter the surface is, the better off you will be.
     
  8. Garra671

    Garra671 Junior Member

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    As well. The new headgasket i purchased is a blue MLS headgasket by felpro, they reccomend almost a mirror finish 70Ra and lower

    I was looking online and read that composite headgasket have more leanancy for rougher surfaces.

    Would i be better off going with one of those?
     
  9. SFO

    SFO Senior Member

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    Not sure if the block would be the same, but @The Critic mentioned restoring the head to a surface finish of 20rA in his HG thread.
    Stay with the MLS, though I'm curious about the composite, if you have the part # handy. Now that @The Critic has been pinged, you might get some additional input on the finish etc. Be sure to read his linked thread for tips and missing parts that might be helpful.
     
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  10. cnc97

    cnc97 Senior Member

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    When I was cleaning my Gen 3 head to install on the Gen 4 block, I did the sandpaper on a board treatment to knock down the high spots. I did 1000 followed up with the 1500. 30 seconds to a minute was all it took per grade of paper. But the finish recommended is the same for the block or head. Flat, smooth, and clean.


    Now that the head is off is a great time to rotate the crank so all pistons are half way up/down the bore and pour a can of Seafoam or Lucas Engine Treatment in each cylinder. Take the crud off the top of the pistons and also soak thru to the rings as well. Just make sure to drain the oil pan and refill with fresh oil before restarting after assembly.
     
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  11. Garra671

    Garra671 Junior Member

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    will I need to buff after the 3000 grit? To get the mirror finish.
     
  12. cnc97

    cnc97 Senior Member

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    I personally did not follow up with 3000. Mine has lived the last 25k miles and not lost a drop of any antifreeze.
     
  13. Garra671

    Garra671 Junior Member

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    So you did 1000-1500 and called it quits it was done? No buffing or anything more?

    Also what did you wet it with?


    I just went out and bought. 1000,1500,2000,3000
     
  14. Garra671

    Garra671 Junior Member

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    @cnc97

    I just used 1000,1500,2000,3000.


    Used each for about 10 seconds.. wet.

    The small scratches that were there, are no longer felt at all.

    however the small leftover black spots of gasket. Are still present.



    side note. How does it look as of right now?...

    My fingernail barely catches on the black spots. And nothing else.
    As well. I just can’t seem to get those 2 black spots off.. unless i really lay into it. Which I’m afraid too do. Do you think those 2 black spots will effect the sealing much at all? I’m thinking about just reassembling and hoping..
    C18F600B-7BBD-48C9-888D-28F673D2A33A.jpeg 1489B2F7-CF53-4C78-A1FF-D3BFFB39E21F.jpeg D1B3FBD2-BDBA-486F-AC95-D90DF1AF3A71.jpeg
     
    #14 Garra671, Dec 4, 2020
    Last edited: Dec 4, 2020
  15. cnc97

    cnc97 Senior Member

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    That is pitting, representative of what happens when combustion gasses meet coolant. You can work at it until they completely disappear, or when you can “see it and not feel it” call it good to go. If they are small, say the tip of a ball point pen, they should be ok.
     
  16. mjoo

    mjoo Senior Member

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    FWIW what I've done with old valve cover material (different car) is apply some acetone and use a fresh razor blade to scrape off material. I keep the blade as flush as possible to avoid scratching. Then wipe off with paper towel. It worked well.
     
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  17. Garra671

    Garra671 Junior Member

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    I don’t think it’s pitting. It raises just ever so slightly. Doesn’t “pit” downwards like a crater.

    I’m going to try acetone or thinner and a metal razor. If that doesn’t do it. I’m going to possibly try a slight more sanding. And then just go for it..
     
  18. cnc97

    cnc97 Senior Member

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    The angle in the pics looks like pitting. I think you’ll be fine if you go for it.
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

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    There's hard plastic "razor blades" available; I keep meaning to order some, for wheel weight adhesive residue. And a 3M spray adhesive remover, might be this:

    3M 38983 General Purpose Adhesive Remover - 12 oz.


    In that link there's also a link to plastic razor blades.
     
  20. SFO

    SFO Senior Member

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    When the 'gasket blasters' did a complete (for them) head gasket replacement in under 2 hrs total, they used a can of brake cleaner and a razor blade to very briefly clean up the surfaces.

    Maybe try one of those "magic eraser" sponges, and report back if it works. If not concerned about contamination, some have used scrotchbrite sponges and WD40.

    If you're still full on OCD, this product is supposed to work quite well : 18 oz Chisel Gasket Remover | Fastenal