Advice on gen 4 engine into gen 3

Discussion in 'Gen 3 Prius Main Forum' started by robomoto, Dec 20, 2021.

  1. Prius_10_inside

    Prius_10_inside Junior Member

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    Thanks 4 ur repost
    the video is great.. I’m still “at a bit of a loss” on what hoses should stay on the Gen4 if re-using the G3 re-circulation pieces.. Hopefully this will make more sense later on … I’m not a mechanic but I have credits in physics and a community college course in electrical (appreciate the welding work…)

    “- Replaced the 4th gen goose neck coolant outlet with a straight pipe outlet - same as gen 3.
    - Installed the temp sensor on the gen 4 head in the same location as the gen 3 head. Did they drill and tap a new hole for this?
    - Installed a straight pipe on the gen 4 head in the same location as the gen 3 head. This is for the coolant hose that goes to the bottom (inlet) port of the heater core. Did they drill a new hole here?”

    … hope my English writing credits are paying off .. I know I’ll see more about it later
     
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  2. Prius_10_inside

    Prius_10_inside Junior Member

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    Yep, am still stuck here, I can see the differences but don’t understand how to get around them
     

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  3. christian cox

    christian cox Member

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    Can you advise me on the specific model # to do the transfer ? I just bought a 2016 engine and after the transfer it runs for a few seconds then quits. I ran a diagnostic which returns cam, maf , temp, knock & water pump of which I’ve never had any issues with befor the swap. Should I swap an ecu too ? Please help if you can. Thanks
     
  4. RightOnTime

    RightOnTime Senior Member

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    Start with the ground wires that attach to the valve cover. Very important to get the proper ground also need the engine codes that popped up
     
  5. christian cox

    christian cox Member

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    Engine codes are the ones I listed . I used a OBD2 scanner . And as far as the ground wires I took my grinder and cleaned off that left corner of the engine and cut and twisted that group of wires together put them under a very tight bolt. So I do not know
     
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  6. ChapmanF

    ChapmanF Senior Member

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    You didn't list the codes though; those are five letters and digits where the first one is P, C, B, or U, the second is zero, 1, 2, or 3, and the next three are digits or A, B, C, D, E, or F.

    We can give better suggestions when we know the codes. If one is a cam code or a MAF code, we can see that easily enough by looking it up. But we can't go backwards from your paraphrase to reconstruct what the original codes were.
     
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  7. EH6TunerDaniel

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    I did this swap last weekend and am doing another one this weekend (if parts come in in time) and I ordered both hoses 16573B and 16571C as well as that plastic piece 16577C. Well the plastic piece has a spot for a sensor that isnt shown in the diagram so I couldnt use it or block it off. I ended up using that short top hose (73B) and I cut the gen 3 S pipe to between a 45 and 90 degree bend leaving in the nipple for the tee for the small coolant hose. Everything else basically goes back how it came out.

    I also reused the gen 3 upper coolant hose, i couldnt use the other one i ordered (71C).
     
  8. EH6TunerDaniel

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    Did my other swap today. Ended up using all gen 3 hoses. I cut the metal “S” shaped water pipe at an angle that worked for me and left the coolant hoses nice and happy. No need for gen 4 upper coolant line hoses.
     
  9. christian cox

    christian cox Member

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    What year is your Prius ? The reason I ask is I suspect possibly my 2011 isn’t compatible with the swap. It runs for a few seconds then stops. I hooked up techstream and well it was useless, worked as well as a generic OBD2 scanner from Walmart. It just couldn’t connect but it did give me a cam sensor and a water pump code. Both of which I never had before the swap. This car is making me feel criminal insane. I think my old engine is going back in after the head comes back. Also I wander if it matters what model ecu my 2011 has in regards to the type of 2016 engine I swapped??
     
  10. ChapmanF

    ChapmanF Senior Member

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    This could turn out to have a very simple and easy-to-fix cause.

    But sometimes the simplest causes to fix are not the simplest causes to find; sometimes they will elude you until you knuckle down and just say "I'm going to get the manual and diagrams in front of me and just rule out the suspects one by one until I have it." Rule out by testing, that is—not by just swapping every possible thing (which takes a lot of time and a lot of money).
     
  11. christian cox

    christian cox Member

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    . These from techstream are the codes. Still haven’t figured it out. I recharged the hybrid battery and it’s weird but after having the battery out and the 12 volt disconnected It still said check hybrid system when I turned it on . Shouldn’t that clear when you disconnect all the batteries. I even pull white main from the fuse box in the engine bay also, Any ideas ?? 2C64C29D-5465-44F3-8B16-1C85910F02CF.jpeg FA6508D7-6188-41D4-B377-C4C969AA83D5.jpeg 2C64C29D-5465-44F3-8B16-1C85910F02CF.jpeg FA6508D7-6188-41D4-B377-C4C969AA83D5.jpeg
     
  12. ChapmanF

    ChapmanF Senior Member

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    P261C won't stop the engine (at least not until it hits 105 ℃).

    P0343, on the other hand, means the cam sensor output has been stuck at 4.7 V+ for four seconds (a cranking Prius sounds like it "runs" for that amount of time) and probably aborts the start at that point. Not much the ECM can do to run the engine if it doesn't know where the valves are.

    This ought to be explainable with a series of questions sort of like this:

    • Is the cam sensor output really stuck at 4.7 V+ regardless of engine rotation? Measured at the sensor?
    • How about measured at the ECM?
    • Does the ECM say the input is 4.7 V+ even when a meter says it isn't?
    • If I supply a voltage to the ECM that isn't, does the ECM still say it is?

    and then what needs to be done is kind of determined by the answers.
     
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  13. EH6TunerDaniel

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    Both cars I swapped were 2010s. 1 got a 2017 engine and one got a 2020. Your car is absolutely compatible with a gen 4 engine. I would say just like Chapman said I dont think your engine is actually running. When I was priming the oil pump I disconnected the harness from the injectors and when Its cranking it does sound like its running. I think you have an issue with it not starting.
     
  14. christian cox

    christian cox Member

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    It’s throwing other codes as well besides two. P0102, p0113, p0328. Tech stream only came back with a couple of codes and couldn’t really connect with the whole system I don’t understand what is off-line I have checked the wiring harness I’ve checked everything I’ve had this point I’m almost willing to just take it to a dealer and have them do something that I can’t do . I don’t know what it is but if They can figure it out you know it’s all the same to me. Any ideas anyone??
     
  15. christian cox

    christian cox Member

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    Yes I definitely agree I turn the engine over by hand trying to see if it was in time and I saw plenty of oil coming through it and I pulled the plugs the plugs looked like they had I had fired some they were darker because I clean them off of the wire brush before I put them back in so this point I’m not really sure what tests I can perform to narrow it down.
     
  16. EH6TunerDaniel

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    I think you need to check those grounds again. Terminate them correctly and bolt them down.
     
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  17. christian cox

    christian cox Member

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    I’m not sure if there’s another way , but I wound them together and ground them the engine the body after I used my grinder to clear a new new surface. I’m going to disconnect them and try ignition again to see if there s difference.
     
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  18. christian cox

    christian cox Member

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    Any of those shop in or near Cincinnati, Ohio ???
     
  19. EH6TunerDaniel

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    Here is how I did mine. I didn’t like that part hanging out the back so I soldered it after I took the pic. I bought a ring terminal from the hardware store for like $1.19 and crimped them in. They are super secure and not going anywhere and they make a great connection.
     

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  20. christian cox

    christian cox Member

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    Looks good. You know I was wondering I read here an article on here were a guy did a regular engine swap in his GEN three but after he did it his car wouldn’t start so he had to get his ECU flashed and that makes a little sense to me because since my engine swap I’ve gotten all these sensor codes but in my original engine I didn’t have any of those codes and I used all the same sensors from my old engine well and and also even the new engine the sensors it came with I still had the same issue and that’s why I swapped them over so I’m thinking it it has to be the ECU and I checked the timing it was perfect. So I do not know