Head Gasket Swap - Questions

Discussion in 'Gen 3 Prius Technical Discussion' started by andreimontreal, Apr 15, 2026 at 2:36 PM.

  1. andreimontreal

    andreimontreal Active Member

    Joined:
    Jan 30, 2019
    389
    118
    40
    Location:
    Montreal
    Vehicle:
    2012 Prius
    Model:
    N/A
    I'm looking on Amayama for a gasket kit and the overhaul vs grind kit is less expensive. Doesn't make sense - apparently they're both Toyota. From what I know Amayama is all genuine parts, right? Based on other parts, they might be Daihatsu parts (still Toyota, but "cheaper") - but it's not stated there.

    Rebuild videos often have Felt Pro - are those better than OEM?

    What is the "SUBS" package supposed to offer? It looks the same as the first one.

    I read that some take the head to a machine shop for a valve job and to get the head's mating surface checked. Is this really necessary? In other videos, I saw the mechanic scrape the old gasket sealer with an olfa blade, sand with a very high grit to make sure the surface is clean and that's it.

    I'm at 237k km (147k mi). I want to do a proactive overhaul/cleaning just to make sure everything is in good shape; 2012 3rd gen. Trying to extend this car's life a few more years. So, water a pump change, spark plugs, egr cleaning etc going down Nuts N Bolt's list all is in order. I suppose that should take care of it, right?
     
  2. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    7,856
    4,003
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    It's best to go with Toyota, with your vin, you know you'll get the correct parts.
    Just get the FULL head gasket kit.

    I scrap off the head, and block, with a razor blade. I just don't gouge it. Using super fine
    sand paper without pressure too hard would be okay.
    They you need a metal straight edge, one you KNOW is perfectly straight, lay it across the head
    from end to end and shine a flashlight on one side and look on the other side. You shouldn't see light
    except where the valve are in the head, obviously. But between you should NOT see light.
    You also want to place it around the head to make sure it's flat. If you see light, the head is likely warped.
    Machine shop time.
    If not, it's not warped.
    You can place the head, matting surface down, on a flat table. Then spray WD40 into each intake and exhaust
    port. Spray enough to cover each valve. Let it sit for 15-20 minutes. Then carefully lift the head. You could
    put rags in the port, then you can flip it over and check the valves carefully to see if any are leaking.
    If you see don't see any WD40 leaking through, the valve/seats are sealing correctly.
    If you see ANY fluid, then you can use valve grinding compound to seat them in.

    It's what I did with mine as I had just a little seepage on one valve. I wasn't really sure if it was leaking.
    84,700 + miles and no issues with mine.

    Or you could just take it to the machine shop and let them check everything.
     
  3. Mendel Leisk

    Mendel Leisk MMX GEN III

    Joined:
    Oct 17, 2010
    61,020
    41,962
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Engine overhaul gasket kit for Toyota Prius ZVW30L-AHXEBK, 12.2011 - 11.2015 - Toyota North America Car and Auto Spare Parts - Genuine Online Car Parts Catalogue - Amayama
    ^ For reference, you're looking at this page?
    I'd take the part number from there, and then for corroboration, plug it in at Toyota USA parts:
    Genuine Toyota Parts and Accessories: Official Online Store | Autoparts.toyota.com
    enter your vehicle and year (or VIN), and check for compatibility

    That said, you're doing a head gasket replacement preemptively? I'd do the other stuff, but wait-and-see on the head gasket.

    You can check the flatness of the head (and block) with a machinists straight edge and feeler gauges. Flatness pecs are in the bottom link in my signature. (on a phone turn it landscape to see signatures)
     
  4. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    7,856
    4,003
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    You've only got 147,000 miles on it? Do you do a lot of city driving? Or highway?
    If you drive mostly city driving, that might be a good mileage to do it, BEFORE it fails.
    That's what I was planing for mine. I had everything I needed, I was just planing the
    best time to do it. But it started to leak.

    If you plan the time, then there is less stress to GET IT DONE. You can take your time, and no pressure.

    Take your time and triple check everything, and you'll be fine.