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Overheated Prius Motor, Have some questions.

Discussion in 'Gen 3 Prius Technical Discussion' started by michaud85, Jan 19, 2020.

  1. michaud85

    michaud85 Member

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    Hello all, recently I had the pleasure of destroying my girlfriends 2010 prius ICE after changing her headlights. I disconnected the coolant overflow hose to get access to passenger side bulb. Well I got a phone call and quickly connected the new bulb closed the hood and drove the car several times over the course of a week. She just drove it about 100 miles to her friends house. no issues. On the way home her check engine light came on and I missed a call from her and didnt call her back till she drove about an hour at highway speed.

    She called me a told me her heat wasnt working and the car was acting funny..... I knew immediately there was a major issue. I knew the engine was already toast when she told me its been like that for an hour so I told her to just drive it home. I saw the coolant overflow line disconnected and i coudnt believe i actually just destroyed an engine by making a mistake changing the headlight.....Just had a fresh oil change, the oil was filthy headgasket failed for sure, I highly doubt it can even be rebuilt I bet the cylinders are warped especially how fast it cools down in this winter weather.

    Anyways, I think im going to swap in another 2010 prius motor from ebay or a junk yard that can confirm the engine was running. I know the hybrid system is separate from the ICE cooling system but im just wondering if theres anything else I might have screwed up other than the internals of the engine? Is there any programming or sensors that are individually tracked by the ecu? I think it should just be a straight forward swap but you never know with these modern cars.

    Any help would be appreciated. Also, the kicker here is I am a professional mechanic. I dont think the block or the crank shaft will even be in condition to be rebuilt and I honestly dont have the time right now for that. I can do a swap in a weekend. This is easily one of the most ridiculous oversight to consequence ratio I have ever experienced.
     
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  2. Raytheeagle

    Raytheeagle Senior Member

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    Welcome to Prius chat(y).

    Mistakes happen, but there are videos here to redeem yourself:).

    @Ragingfit made videos of swapping in a Gen4 engine (2016 and newer) which is better than the one that was there;).

    Worth looking for and watching with what you have lying ahead(y).
     
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  3. michaud85

    michaud85 Member

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    Brother, I went from feeling horrible like I was going to start a new life somewhere else to kind of excited to do a motor swap haha. The 2016 engines are way cheaper and have far less miles(obviously)? What makes them different or better?
     
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  4. Raytheeagle

    Raytheeagle Senior Member

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    Toyota update the piston rings and guides which leads to less potential for oil burn:).

    Also might be more resistant to head gasket issues;).

    And less expensive, so worth the effort(y).
     
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  5. Cosmo Tigato

    Cosmo Tigato Active Member

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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Was there any warning lights on the dash?

    It ticks me that there's no coolant temp gauge on the Prius; most any econobox car has this. :cautious:

    Here's a link to the 4th gen engine swap @Raytheeagle mentioned; it's in a kinda odd-ball location:

    Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v | PriusChat

    Maybe in that thread, towards the end, there's someone who also managed to get the 4th gen EGR to work in a 3rd gen car, utilized the 3rd gen exhaust manifold, but heated and bent the EGR connection pipe.
     
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  7. ChapmanF

    ChapmanF Senior Member

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    This seems like a good place for a note that might save future readers some excitement:

    A lot of cars, especially older ones, have a coolant overflow bottle, including Prius Gen 1 and Gen 2. That bottle is attached by a little hose to right where the radiator cap sits on the radiator, and fluid only goes into the bottle when some expands past the radiator cap when warm, and gets slurped back into the radiator when the car is off and the fluid cools and contracts. Leave off the hose from an overflow bottle, and the most that will happen is a bit of coolant might escape when the engine gets hot, and a little air get sucked in when it cools.

    A lot of newer cars, and with Prius this starts in Gen 3, have not a coolant overflow bottle, but a coolant degas bottle. It's the same kind of looking plastic bottle, but it is stouter, holds pressure, has two connecting hoses, and is always in the coolant circuit when the engine is warm, with coolant being pumped right through it. Leave the hose off a degas bottle and driving the car will pump the engine coolant right out. :eek:
     
  8. michaud85

    michaud85 Member

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    Probs the exact face I made when I saw the hose. What a nightmare mistake.

    This is actually pretty messed up on Toyota. If the car doesn't have these absolutely vital guages available, at least have some sort of message system or extremely effective limp mode that doesn't allow you to drive 75 mph on the highway with zero coolant.... The only dash indicator was a check engine light. Now I may be jaded from driving cars for years with CEL. But I don't think anybody pulls over and opens the hood Everytime a CEL comes on like something horrible just happened. Usually you can drive around for a few years with a CEL because it's something harmless. Without an OBD reader literally in the car(not a bad idea in the future) there's not much you can really do. She should have probs pulled over when she felt heat wasn't working and CEL on but it's enormously tempting to not stop on the side of the road far from home with no heat..... btw check engine light was showing I think P0117 bad engine coolant sensor.

    stilll feel pretty horrible about this, I don't have a garage and the weather has just been brutal. But life will go on I suppose.

    I spent like 15 mins prepping her to say listen this car may never drive again, noting how changing the oil late leads to the horrible consumption we've seen(rude to make her feel like it's her fault anyways), turns out I'm just a big jerk! I came clean about the hose and told her, although I was doing a piss poor job disguising my discovery if I was trying to hide that fact, we literally found my watch that wen missing a week ago on top of the oil fill cap! Haha! At least now noone we know will ever ask me for help fixing their cars and I probably will never help anyone fix their car again.

    Also it will be nice to put a motor in there that isn't consuming so much oil. Holy crap her car would eat oil. So if I can swap In a motor for around 1k and give her a few more years with this car she loves that will hopefully be great. But the thing is it's got something over 200k so I'm worried soon something else in the electrical side will go like the battery or idek. Never work on cars unless I have to. I said I was a professional mechanic but I work on Airplanes lol.

    Thank you for all of the replies. If I do a motor swap I will try to document it pretty well especially if I come up with some different tricks or tips. I'll be sure to post a thread here for future Prius owners to learn from.

    I honestly will say I have no problems driving the Prius and actually enjoy it.
     
    #8 michaud85, Jan 20, 2020
    Last edited: Jan 20, 2020
  9. Cosmo Tigato

    Cosmo Tigato Active Member

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    I just did a swap on a 2012
    Just Bought a 2012 For $700 with a Blown Head Gasket | PriusChat

    If you want I can help you do yours.
    I think there is a B&R auto in Salem
    I live in The Rogue Valley Southern Oregon.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    I'm sure there is at least one, maybe more, temperature sensor(s) in the engine and coolant circuit, and the car does have some way on the dash to tell you about a measurement out of range. But I'm not sure exactly what the sensor might be measuring if the coolant has left the building. They might not have anything built in that's especially good for detecting that case. (You'd think maybe it could notice reduced effort at the electric water pump ... but somebody would have to have written code to check that.)
     
  11. Cosmo Tigato

    Cosmo Tigato Active Member

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    Could we wire up a coolant temp gauge to our prii?
     
  12. Grit

    Grit Senior Member

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    I use an app for that, works great and always drive with the app sync'd to the car for real time data.
     
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  13. Cosmo Tigato

    Cosmo Tigato Active Member

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    Would ScanGauge II also work?
     
    #13 Cosmo Tigato, Jan 20, 2020
    Last edited: Jan 20, 2020
  14. ChapmanF

    ChapmanF Senior Member

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    What we want for this exact situation is a no-coolant temp gauge. The with-coolant temp gauge already comes with the car (and can be read over OBD-II, as already suggested).
     
  15. Grit

    Grit Senior Member

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    Scangauge is not an app. Below is an app:

    IMG_0487.JPG
     
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  16. Cosmo Tigato

    Cosmo Tigato Active Member

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  17. michaud85

    michaud85 Member

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    Cosmo, I'm in Salem MA, but that's very generous of you to offer.
     
  18. Vman455

    Vman455 Senior Member

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    The Scangauge 2 will also read and display engine coolant temperature.
     
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  19. Cosmo Tigato

    Cosmo Tigato Active Member

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    I will dig mine up, now to go through boxes in the garage :ROFLMAO:

    Thanks
     
  20. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Waiting for the popcorn.....
     
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