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Bad knocking from top of engine...won't start

Discussion in 'Generation 1 Prius Discussion' started by Blotto, Nov 30, 2018.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    Are there O-rings around each spark plug wells? Maybe time to take the valve cover off, replace all gaskets.
     
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  2. padroo

    padroo Senior Member

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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    In the link they say to get the cylinder being tested at Top Dead Center. Eric the Car Guy says TDC and on the compression stroke. It's beyond my comprehension, but I wonder why Eric's saying that.
     
  4. padroo

    padroo Senior Member

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    Because all the valves are closed.
     
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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    So they're all closed on compression stroke TDC, but not on exhaust stroke TDC? That's what I was gleaning from Eric. The link above doesn't seem to differentiate though.
     
  6. Blotto

    Blotto Junior Member

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    Padroo,
    Thanks for the advice - I can't argue against that.
     
  7. padroo

    padroo Senior Member

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    I see your point.
    I haven't done an engine leak down test since 1970 on a Pratt & Whitney R-985-AN-14B Wasp Junior engine while I was in aviation school.
    Some of the details have slipped my mind. :)
     
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  8. Blotto

    Blotto Junior Member

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    Padroo,
    I was planning on doing a compression test (since I already have a compression tester) but, now I think about it, I'm not sure it can be done on a Prius - I mean when you turn the key, the engine has to turn over - that doesn't happen in a Prius, does it?
     
  9. FireFighterHill

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    Did you clean the COPS? I dont remember if the boot and spring inside detach from the actual coil. If it does clean and inspect. If the boot or cop itself has any cracking they are trash. You should be able to ohm out the cop to give you an idea if they are any good. But once they get a crack everytime they heat cycle they suck in moisture and corrode.

    SM-N960U ?
     
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  10. padroo

    padroo Senior Member

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    That's one reason I like the leak down tester over a compression gauge on a Prius. It will also help tell you where your leakage is also. Adapt an old spark plug and put air directly into the cylinders and then you can listen to the intake, exhaust pipe and take the dipstick out or the oil filler cap and see how much air comes out. IF YOU HAVE VERY LITTLE YOU ARE GOOD.

    HOW MUCH OIL ARE YOU USING?
     
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  11. Blotto

    Blotto Junior Member

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    Yes, but just to get the oil off - didn't notice any cracks but today I'll take them out and have a good look.

    Have not been making a note of oil usage but I definitely need to add more oil between changes...roughly 2 or 3 qts every 3 or 4k miles...just a guess really.

    As for the leak down, on my old stick shift MG you could put the car in gear and nudge the car forward, looking at the valve train for TDC (unscrew 2 nuts to get the valve cover off). I need to do see some reading up ... on a Prius can you do the same?

    Thanks!
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    You're one up on me: I haven't done one since forever.
     
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  13. Blotto

    Blotto Junior Member

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    Today I took them out and gave them another clean - no cracks or tracking, but #1 COP had baked on fondoo that wouldn't come off. Also noticed than the rubber boots can be twisted off. That allowed more cleaning.

    Still got same error codes - #1,2 4 misfiring.

    The fact that #3 seems to be behaving has given me hope that the problem is not due to a slipped timing chain or other mechanical issue.

    Anyways, I've ordered up new plugs, coils, valve cover gasket. Hopefully they will arrive before the forecasted snow!
     
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  14. Blotto

    Blotto Junior Member

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    Yo Brian,
    Where's this 5% code?
    Thanks!
     
  15. FireFighterHill

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    Move the cop from the non misfiring cylinder to the other cylinders. If the misfire follows the cops you know that's the problem.

    SM-N960U ?
     
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  16. Blotto

    Blotto Junior Member

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    Brilliant!
    Many thanks - I'l try that tomorrow!
     
  17. Blotto

    Blotto Junior Member

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    Swapped the coils from 1,2,3,4 to 4,3,2,1.
    Really bad knocking so I switched it off.
    Didn't get any error codes, probably because it didn't have time to gather information.
    Think I'll wait 'til I get the new plugs, coils, valve cover gasket.
     
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  18. Blotto

    Blotto Junior Member

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    Well, you are not going to believe this but:

    Prius Lives!!!

    I put in a new valve cover gasket, plugs, cheapo coils, and PCV valve.

    Started right up and I drove it to town, as smooth as you please.

    Many thanks for all the help and advice I have received!

    Cheers!
     
  19. FireFighterHill

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    Glad to hear! These gen1's are almost impossible to kill if you just maintain them! People see hybrid and automatically assume they cant be repaired by a home mechanic. Might I recommend some preventive maintenance? Such as inverter coolant flush, transmission fluid change, dropping the pans for cleaning and installation of rare earth magnets, PVC valve replacement, and flushing the radiator.

    SM-N960U ?
     
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