1. Attachments are working again! Check out this thread for more details and to report any other bugs.

How long will prius crank if no start is detected?

Discussion in 'Gen 2 Prius Main Forum' started by Prius92, Jul 31, 2024.

  1. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    Swapped a replacement engine. I think the hybrid battery might be low.
    Go to start it, all I get is a clunk and nothing. Won't even turn over.
    If the engine had been sitting a while, could it need rotated by hand to free anything up?
    I've asked 2 dealers how much it would cost to have the hybrid battery charged, but they all keep telling me "the 12v battery starts the car" which isn't correct.
    So my question is, say you took the injectors and plugs out, how long would it try to rotate it before stopping?
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,404
    6,062
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    If the car goes to ready condition, and you hear a clunk as the engine tries to start, you have a big problem. Something in the driveline (engine or transaxle) is seized and preventing the engine from turning.

    Did you turn the new engine by hand prior to installing it? I have a spare engine, still mounted to its transaxle, slated for installation this fall, and I can rotate it with a socket/ratchet with very little effort.
     
  3. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    So there was a cylinder stuck. I got it freed.

    But have another issue...I think the hybrid battery ran out.

    Oddly, when you go to start it after reconnecting the 12v, it shows full bars, then within 5 seconds floats down to 1 bar.

    It ran about 2 seconds then stopped.

    Other odd thing, the ready light flashes.

    I'm going to hook up my bluetooth scan tool later and see what's up/
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    7,427
    6,913
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    That's a strong suggestion that the hybrid battery can't hold much of a charge anymore, it's toast.
     
  5. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    Now what?
    Is it going into some kind of failsafe mode?

    Seems to be stuck to the 1 low voltage module.
    The others look good, so it appears to be affecting the SOC.




    [​IMG]
     
  6. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,107
    410
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    Use a volt meter to measure the total HV battery voltage and compare it to what is being shown in the Dr. Prius app (201.59v). If you measure about 201.59 volts, you need to use a grid charger to charge the HV battery.
     
    #6 Brian1954, Jul 31, 2024
    Last edited: Jul 31, 2024
  7. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,107
    410
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    When you disconnect the 12v battery, the HV battery SOC is erased from the hybrid control ECU. When the 12v battery is reconnected, the hybrid control ECU uses a default SOC of 60% until the ECU has time to recalculate the actual SOC again. So after recalculating the SOC, the battery graph goes down to 1 bar. This is telling you that you have a very low SOC in the HV battery. It does not mean that your HV battery is bad.
    The car is not running during those 2 seconds. The electric motor is trying to start the engine for those 2 seconds, but it is not running.

    Have you tried using a scanner to check for trouble codes?
     
    #7 Brian1954, Jul 31, 2024
    Last edited: Jul 31, 2024
  8. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    A couple codes related to the throttle position sensor, I'm not sure if I hooked it back up right, could that cause an issue?
     
  9. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,107
    410
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    Yes, that could cause the engine not start.

    Please read all the trouble codes and list all the current codes you have. The actual code like P0121, etc. Not the description of the codes.
     
  10. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    Before it starts, I hear the throttle moving back and forth a lot. i think when I took the cover off, I didn't align the sensor to the throttle correctly.
     
  11. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,404
    6,062
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    How in the world do you just get a 'stuck' cylinder? And why in the world would you put that engine in your car without further investigation of why it was stuck or what damage was caused to the cylinder wall? Pistons don't just get stuck. Water in the cylinder? Corrosion bonding the rings to the wall?
     
  12. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,107
    410
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    The sensor in the throttle body is factory calibrated. If you took the cover off, you will never get it put back in the correct position. You need to replace the throttle body.
     
  13. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    Had the engine rebuilt, due to a divorce the car sat for a year, but had a tarp over the engine (spark plugs installed) as well as the hood shut.

    Somehow a small amount of water got in a cylinder. There was rust stains on the spark plug, but only a couple tiny rust spots on the plug threads.

    Put some seafoam down it and let it sit 4 hours, it came loose.
     
  14. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,404
    6,062
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    Having a Gen 2 engine rebuilt is a pretty rare thing. Sucks to have to let it sit so long. YEARS ago, I had a Ford 429CJ rebuilt while I was on deployment. It was going to go into 1970 Mach 1 that I had an agreement in place to purchase when I returned. Engine turned out beautiful, but car was sold while I was gone. Lesson learned about verbal agreements.... That engine sat in the family basement for 3 years. I never did find another worthy body for it. I hope it works out good for you!
     
  15. Prius92

    Prius92 Active Member

    Joined:
    Sep 14, 2019
    447
    106
    0
    Location:
    Iowa
    Vehicle:
    2008 Prius
    Model:
    II
    Well I foolishly thought I could rebuild it cheaper than buying a JDM low mileage one for $1,600 on eBay (they are now only $1,100-$1,300)

    Ended up costing me around $1,800 all in. Engine machine shops are about double in price what they were 15ish years ago. Was $400 just to have the head done and another $300 to have the block cleaned and ball honed (plated cylinder walls are too hard to pad hone).

    I also bought another core engine for $200 to have extra parts including the little valve lifter buckets.

    I had to put it all back together myself, reseal all the mating surface (timing chain cover, middle oil pan), and check all the valve clearances, all which was a giant pain in the nice person. There is very little wiggle room on your valve clearances, 4/1000 of an inch, the same thickness as a sheet of printer paper. Then the mating surfaces...took 2 tubes of gasket maker. The bead has to be a certain thickness and width in different areas.

    You also have a flywheel damper plate that has to be precisely center to the input spline of the crankshaft. I'm not sure why there are no centering pins on that part.