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Using TechStream for compression test

Discussion in 'Gen 3 Prius Main Forum' started by donzoh1, Dec 7, 2022.

  1. donzoh1

    donzoh1 Active Member

    Joined:
    Jan 19, 2019
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    Location:
    Lenexa, KS
    Vehicle:
    2004 Prius
    Model:
    Five
    I'm thinking of using techstream to test compression prior to engine removal. The car had misfires in three cylinders. It also has broken springs in the input damper so the engine must be removed in any event. Anyway, I have removed the HV battery safety plug, intake manifold and throttle body at this point and unplugged a few sensors.

    Can I get opinions on whether techstream will work for a compression test at this point or what needs to be connected again first? I don't see where it would be prevented mechanically but just wondering whether the computer will allow the compression test.
     
  2. donzoh1

    donzoh1 Active Member

    Joined:
    Jan 19, 2019
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    Location:
    Lenexa, KS
    Vehicle:
    2004 Prius
    Model:
    Five
    I'm also planning a leak down test with and without oil in cylinders after the engine is removed so not sure the compression test is needed.
     
  3. ChapmanF

    ChapmanF Senior Member

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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    I'm not sure I've ever done a Techstream compression test successfully, with either dongle I have. Maybe if I had the $$$ DrewTech one....
     
  4. donzoh1

    donzoh1 Active Member

    Joined:
    Jan 19, 2019
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    Location:
    Lenexa, KS
    Vehicle:
    2004 Prius
    Model:
    Five
    I think my techstream is maybe some asian knockoff or something. Right now, it won't go past the vehicle ID screen which could be because I'm using a Win 7 computer. Anyway, if the people that sold it won't support, I had thought about the 2 day Toyota subscription but most likely will just settle for the leakdown test which will tell me at least what the compression test would. On a related note, I did a compression test with an engine out with a high torque (half inch) electric drill. Actually worked pretty well, although the numbers were a bit lower since the RPM was not that high. I think even that test would likely show a cylinder head issue if there was one.
     
  5. ChapmanF

    ChapmanF Senior Member

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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    I melted the brush holder in a high torque (half inch) electric drill once, doing stuff like that.