Valve lash Adjusters HELP!!!!!!!!

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Dale Casey Acker, Nov 10, 2025 at 10:58 PM.

  1. Dale Casey Acker

    Dale Casey Acker Junior Member

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    Ok I made another post a week or so ago along the lines of this same subject, but I have changed a few things and have a somewhat better understanding of it now so I am going to try again and see if I can figure out this valve train noise. I am 99% sure it is the valve lash adjuster making this ticking noise I can not get rid of. I just did the head gasket on my 2010 and when I got it back together it was ticking HORRIBLY. So I took the adjusters out, cleaned them like this video



    and reprimed them and put it back together with the ticking still there however it was a little quieter. So I go and get some more out of a known working motor, clean them, prime them and install them and again still have ticking although it sounded somewhat different. I have cleaned and changed these several times but still can not get this ticking gone. This is where I am at, I have 2 sets of vlave lash adjusters that I can clean and they will pump up and hold pressure in oil on the bench but whenever I install them it still ticks like crazy. The best way I get them to hold pressure is stand them straight up in a pan of oil and put the tool on the top to depress the ball and push s few times and boom they are tight. I can take them out of the oil, bleed them and then try to get them to pum up without the little tool pressing on the ball and they will never get tight. The second I put the tool on there and press on the ball and push it up and down a few times it will get back rigid again like it is supposed to. So my biggest question is am I supposed to install these things with the fluid out of them initially and run it a little while and hope they fill up and get tight? If that is the case how will they do that if the only way I can get them to hold is depressing the little check ball down with the tool. Or am I supposed to pump them up tight and install ( this will force what fluid is in them out when I sung down the cam shaft retainers) which is what i have done a couple of times and unsucesfully gotten rid of the ticking. Are there any other special install procedures that I am missing when I put these things back in. Any help is greatly appreciated. Dale
     
  2. PriusCamper

    PriusCamper Senior Member

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  3. Tombukt2

    Tombukt2 Senior Member

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    They're something else going on . I don't see a reference to pre charging the lifters . You can pump them up on bench in bowl of oil . To see they do. Wen engine starts they pump up instantly more or less . Maybe oil pump issue . Timing cover based I believe . Have any pressure wen running ?? If they're an oil light there's a switch screw in manual gauge temporary start look at gauge maybe be shocked .
     
  4. Dale Casey Acker

    Dale Casey Acker Junior Member

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    Ok I have a manual oil pressure gauge is there a port I can hook it into?
     
  5. Dale Casey Acker

    Dale Casey Acker Junior Member

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    Also how is oil pressure going to pump them up if I have to depress the little check ball to get them to firm up?
     
  6. ASRDogman

    ASRDogman Senior Member

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    Perhaps those are bad also? If that's your issue.
    The oil pressure pumps them up. If they bleed down overnight, they likely are not any good.
    Did you use a screw drive or tethescope to listen at the valve cover to try to find what area the
    tapping was coming from?
    Are you certain the rocker arms are moving completely and freely?
    Or perhaps a valve is bent?
     
  7. Dale Casey Acker

    Dale Casey Acker Junior Member

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    I used a stethoscope and it sounds like it moves every time I swap out the adjusters. Not sure how a valve can be bent bc it was running quiet and smooth before the head gasket job and actually runs really good now just sounds like a damn swing machine tapping. I'm going to try it one more time today so do I install them squishy or do I pump them up so they are rigid and don't move pre-install?
     
  8. ASRDogman

    ASRDogman Senior Member

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    mmmm I think maybe you forgot one of the little caps? Or maybe didn't tighten something down?
    And if it is moving, then it is possible it is a lifter.
    If you pinpoint it, or get close, maybe use some of the other ones you have free to replace that section?

     
  9. Dale Casey Acker

    Dale Casey Acker Junior Member

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    And not sure what you mean rocker arms moving free because they just sit on top of the lash adjusters and valve springs (and yes the little spring cap things are on)
     
  10. ASRDogman

    ASRDogman Senior Member

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    They are moving, and if something is not correct, if they are sticking, they could be getting slapped with the
    pushrod.

    P.S. I just realized I said push rods.... That was dumb! There are no push rods.
    And we were talking about the rocker arms.... :(o_O

    Sorry about that. Check that they are sitting correctly. You might see wear...
     
    #10 ASRDogman, Nov 11, 2025 at 11:36 AM
    Last edited: Nov 11, 2025 at 2:30 PM
  11. Dale Casey Acker

    Dale Casey Acker Junior Member

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    Alright I will check in a little while when I pull the cover back off.... Do I plan on installing the next set squishy or pump them up rigid?
     
  12. ChapmanF

    ChapmanF Senior Member

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    2ZR has kind of a nice auto-lash setup. Overhead cams, no pushrods, in fact the cams are even over the rockers, pushing down on them. Each rocker rests on the lash adjuster at one end and the valve stem at the other. Result: the lash adjusters just sit still; their mass doesn't contribute to the moving mass of the rockers, the way they did in other engines I've seen where they lived in a moving end of the rocker.
     
  13. PriusCamper

    PriusCamper Senior Member

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    This is a common description for all Prius engines and mechanical repair work based on strange noises in old cars can turn into an elusive nightmare as you're experiencing. My suggestion is to get some perspective and make an effort to seek out and listen to 5 or 10 other Prius like yours and see if they sound worse or better. Perhaps that could give some piece of mind?
     
  14. Tombukt2

    Tombukt2 Senior Member

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    You're talking about buckets with shims under them some are buckets with built in shim others are a literal shim under the bucket . So bucket gets reused. Clearance is measured old shim measured and a new shim ois calculated and put under the bucket. I'm getting ready to throw the 2z atkinson head buckets lifters all of it out .
     
  15. ASRDogman

    ASRDogman Senior Member

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    See post 10, I updated it.

     
  16. Tombukt2

    Tombukt2 Senior Member

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    It will screw in right where you unscrew your pressure switch