Tapping Knocking anyone know?

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by dig4dirt, Oct 1, 2025.

  1. dig4dirt

    dig4dirt MoonGlow

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    I have this tapping/knocking happening

    This only happens during the warmup stages.
    Once warmed up, it does not happen.
    Also, if there is any load on engine during warmup, it does not happen.

    Could this be lifters, rockers, valves?
    I would be interested in replace the lifters, but I just don't know if that is what it is.


    I recently purchased this car just shy of 200k miles. it is a 2017

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  2. EchoEcho

    EchoEcho Junior Member

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    Did you ever get to the bottom of this?
     
  3. dig4dirt

    dig4dirt MoonGlow

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    Nope, still is a thing.
    Has not got any better or worse.
    I put over 20k miles on so far. @218k

    I used some MMO without change.
    I am on my 4th Valvoline Restore and Protect oci

    no change.

    Oh well, I'm sure it is lifters, rockers or valves, but have not opened her up yet.
     
  4. bisco

    bisco cookie crumbler

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    is it a prime or prius c?
     
  5. ChapmanF

    ChapmanF Senior Member

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    Under the hood in the video looks like a 2ZR.

    That's quite a loud tap, sounds like about once per cam rev, so maybe it wouldn't hurt to have a look under there. Maybe one of the hydraulic adjusters has failed to adjust.

    Replacing all 16 lifters might be overkill $$ if one is misbehaving. Unlike the select-fit lifters in the 1NZ engine (with 35 sizes each to choose from for intake and exhaust), the hydraulic adjusters in the 2ZR are identical and if one is bad and you can't get it working, you can just replace it.