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Engine removal and replacement question.

Discussion in 'Gen 2 Prius Technical Discussion' started by John11, Aug 17, 2014.

  1. John11

    John11 New Member

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    I want to remove the engine and trams from my 2007 Prius . Where should I disconnect the wiring harness. Do I need to disconnect each connector and move the harness aside? Or, is there a connector that I can separate to leave the harness connections intact to the engine? Can you suggest a source if how to information for the task?
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    techinfo.toyota.com

    You will need to disconnect each connector.
     
  3. John11

    John11 New Member

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    Thank you for your reply. I was hoping for a simpler solution .
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    An alternative method is to disconnect the wiring harness at the engine ECU located behind the glove compartment. Then thread that harness into the engine compartment. The harness would have to be disconnected from the main relay/fuse box, then the harness could be removed along with the engine.

    However I would question whether that method will save you time because to gain access to the engine ECU you may have to remove most of the dashboard including the passenger-side airbag.

    Further you'll eventually have to disconnect all wiring harness connectors leading to the engine sensors and other components anyway, before you install the new engine. Yes, it would be easier to do that work with the engine out of the car.
     
  5. wa-chiss

    wa-chiss Member

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    Gen II is easier/less of a hassle to unplug connectors from engine. Gen III is easier because the ECM is under the hood.
     
  6. namoom

    namoom New Member

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    I found that while removing the engine through the bottom it was very easy to disconnect everything for the wiring harness, I would recommend it this way considering that there are a lot of sensors that don't have to be unplugged vs if you unplug from your ecu you will have more work IMO
     
  7. wa-chiss

    wa-chiss Member

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    That's the way we do it in the shop. We have a cradle stand that we use. Lower the car down, unbolt the cradle, and lift the car off. However, if my memory is correct, in the Gen II prii, the engine is a structural part of the cradle. It's two pieces that bolt to the engine with the roll mount on bottom. You would have to make a support for the two halves to remove the engine or trans off the cradle. It is possible to remove the engine from the top without disturbing the cradle. I've done it, you just need an extra pair of hands and eyes to watch and guide out and in. Unplug everything from the engine and trans and the harness should lay over the right fender while you remove. If you're doing this in the garage with no lift, then this is how I'd do it.
     
  8. Lam

    Lam Member

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    curious, not to threadjack but, can you remove the engine while leaving the transmission in? is there enough space between the engine and the body to get the engine out? i really dont want to take the transmission out with it.
     
  9. namoom

    namoom New Member

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    There is so little extra to do pulling out the engine and transmission that you will save a ton of headaches if you just pull both. Also with the engine mounts and other secured points I doubt you can just pull the transmission
     
  10. wa-chiss

    wa-chiss Member

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    The problem won't be getting the engine out, it'll be trying to get it back in, lined up, and angled right to mate with the trans.
     
  11. redsidriver

    redsidriver New Member

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    is there a write up on how to remove and install the engine? im going to be doing this pretty soon on an 07 i just bought with bad engine .
     
  12. Lam

    Lam Member

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    Just finished this job using a traditional cherry picker. If you my write-up on how to pull the transmission, that is 80% of the job. The other 20% is just unbolting the exhaust manifold, fuel line, and electrical connectors. The hard part is getting the AC line out of the way.

    Taking the engine out from the bottom is much easier if you have a means of lifting the car over the engine.
     
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  13. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    I unhook the engine wire harness from the ECUs behind the glovebox, then pull the lot through the big firewall grommet. This is easier than undoing every single sensor connector on the engine and tranny, and is how Toyota designed it to be done.

    The best way is to pull the engine and tranny down as a unit with subframe and steering rack left on subframe. Remove wiper cowel and inverter, Unbolt the AC compressor from the engine, unhook it's power cable from inverter and tie it up out of the way so you don't have to evacuate refridgerant.

    Put the engine/tranny on a cart and raise the car. If you don't have a lift put the car high and lower them down onto a dolly.

    I don't think it's easy for the engine to come up, or worth trying to separate from tranny in the car if you need the engine out of car.
     
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  14. Tony Lucero

    Tony Lucero New Member

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    I just changed an engine in a 2014 Prius I found it easy to just disconnect them at the connectors and then just leave the wire harness back over the transmission really simple and easy.
     
  15. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    Gen2 (2004-2009) Prius and Gen3 (2010-2015) are completely different cars. Instructions for Gen2 may not work on Gen3 and vice versa.
     
  16. Dxta

    Dxta Senior Member

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    Yes you can. Remove all the bolts holding the transmission to the engine; engine mounts; wiring harnesses, etc.
    Remove also the water pump, compressor, radiator.
    After that, use a prey bar to shift the engine from the mating surface of the transmission.
    This should be done after removing the pressure plate bolts.
    Use a hoisting chain to clamp the engine, and direct it carefully while jacking it out.

    Hope this helps.
     
  17. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    uhm Prius engines do not have a pressure plate (nor do the trannies have a torque converter) so your comment about removing pressure plate bolts makes no sense.
     
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  18. PollyDaPrius

    PollyDaPrius New Member

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    How do you remove engine mounts, specifically the close to the idler pulley? I've unbolted all bolts but one is giving me issues. Has me perplexed. The washer/bolt at the bottom left photo is where my obstacle lays. What is it, How do I remove it?
    Follow Link for close up photo: Must Be Fixed! It Is Necessary! | PriusChat
     
  19. edthefox5

    edthefox5 Senior Member

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    I believe you have to drop the sub frAme assy,
     
  20. Kermit80526

    Kermit80526 Junior Member

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    still hoping that you can send me your write up on your experience pulling this out the top.

    Thanks,

    Rob