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

I wonder what happens if that's removed. More heat picked up from the exhaust?

 

Maybe. There is an actuator on the cat for the coolant. I'm not sure how it works but I bet Toyota did it right.

 

That's a thermostatic actuator; as it warms it flips the valve in the exhaust, allowing the exhaust gas to go straight through instead of through the heat exchanger.

I'm also pretty sure Toyota did it right, but if they thought a little restrictor was part of doing it right, I wonder what's the effect of changing their minds for them?

 

You may be on to something there.
I didn't notice one on my car but it may have gotten lost during the swap.

 

The Gen 3 circuit is downright weird, because this 87208 pipe assembly down to the exhaust heat exchanger has a tee nipple off the side offering a shortcut right back to the EGR cooler (labeled in absentia here as PNC 25601L).

So coolant from the heater core eventually ends up at the EGR cooler, some after going through the EHRS, and some after going around the EHRS.

That's one of those times where the simple saying "follows the path of least resistance" has to be chucked in favor of the real one, "follows all paths in proportion inverse to their resistance", and you could imagine Toyota putting little restrictor doodads one place or another to tweak how much flow goes which way.

It looks like the coolant that tees off before the EHRS enters the EGR cooler at the aft end, and the coolant coming back from the EHRS enters it at the forward end right near where its outlet is. So the coolant that hasn't been sent to the EHRS is what's doing most of the cooling in the EGR cooler, which makes sense, as it won't be as hot.

 

Plumber’s nightmare.

 

folks, so I have been on this long journey to do this upgrade to my 2013 Prius V. I was finally able to get a replacement gen 4 motor a few weeks ago. A friend of mine that happens to be a toyota tech was suppose to help me do the swap. He has done many engine swaps in the past but this retrofit is first of its kind for him. I was still in the process of doing all the research and getting my ducks in order to do the retrofit, I have watched all the videos and have read through at least 60% of this thread. So my friend showed up today to help me knock out this project, we spent 4 hours and right now the new motor is out and the engine bay is ready for its new heart.

The favor I am here to ask is if someone can kindly let me know if I am missing something or a step that I need to make sure I perform to have a smooth engine swap. I am pretty sure there is heaps of info in the later part of this thread that I havent read yet as I am short on time as him and I are planning on finishing up the swap tomorrow.

- The gen 3 flywheel and damper needs to be swapped over to gen 4 motor.
- The side exit coolant pipe on gen 3 needs to be altered a bit with a 6" one inch galvanized pipe in order to be used with the lower coolant hose.
- The temp sensor plug on the factory harness needs to be extended.
- The coolant overflow hose needs to be cut right near the throttle body area so a T connection can be installed to link the coolant line from the throttle body to the hose.

I am eternally grateful for the in depth video series that has been posted on youtube as its a great resource and has most of the answers that I am looking for, if there is a better alternative or upgrade to some of the steps that have been taken in the swap video since it was posted then I'd appreciate if someone can elaborate. Any help would be greatly appreciated, in the meantime I am going to spend a few of the next hours to see if I can go through the rest of this thread.

 

Yes that looks right, I would use an 8" piece of 1" pipe from home depot.
And you have to cut a nub off the engine to make room for the 3rd gen EGR cooler.

 

Thank you so much for all the videos, this swap couldnt have been done without them, I was able to drop the new block in yesterday, everything went smooth. I am using the water pump that came with the new motor, it had to be taken off in order to get the motor in without too much trouble.

The AC compressor is on, the exhaust manifold is on, pretty much all the hardware is on, I guess it was a bit ambitious of me to think I'd be able to start it yesterday but we did get a lot done. Now comes the fun part of plumbing all the hoses etc. I was stupid not to lengthen the temp sensor wire rather I pulled it out of the factory harness and got 4" but that isnt enough, unless you undo the plastic covering on the harness and do a bit wire pulling from the loom.

Luckily I do have a 2010 Prius hatchback as well (next in line for a gen4 swap as well) to check for the location of all the hoses etc.

The old EGR and intake has been thoroughly cleaned as the cooler was completely plugged with carbon and the EGR ports in the intakes were all gunked up plugged as well.

More updates to come.

 

More’n likely the culprit.

 

There's a guy on here selling temp wire extensions. Great way to do it!


RightOnTimeSenior Member
Start a Conversation
Joined:
Sep 21, 2012
589

1,394

183
Location:
Kidnapped in OC, CA
Vehicle:
2012 Prius Plug-in
Model:
Plug-in Base
Since our Shop has done so many of these transplants, I decided to piece together a harness that is plug and play to extend that dang water temperature plug sensor. If anyone is interested please contact me at: [email protected]



$12 which includes free shipping in the United States

 

Nice! how do I get one?

 

Ragingfit
Tom The Engineer
- Fix That Prius !!!

My address is:

Thomas E. Bourassa
2598 Roseglen Way,
Aurora, IL, 60506

 

Ahh, kind of late now. I was able to solder a 6" piece of wire and extend the connector. May be for the next project I'll pick up one of the above harness.


Swapped the lower hose that runs the front length of the motor, coming out of the water pump to go towards the EGR cooler, installed the EGR cooler, took out the old steel pipe fitting the runs on the 4G motor right below the EGR cooler, starting to make progress.

I am running into a small hick up though, there is a small outlet coming out from the side of the engine, its facing towards the front and sits right under the inlet for the 3Gen EGR cooler, with the hose connected to the EGR cooler hose and EGR cooler bolted to the exhaust pipe it does not leave any room for a hose to be slipped onto the pipe. Is this outlet suppose to be plugged? If so I can probably take the fitting off, pull the small pipe out, thread the hole and plug it with a sealed bolt.

 

Package is on its way to you!

 

Never mind its for the coolant overflow line, the one that need the Pex Tee. The 3G prius line has some anti chaffing mesh on it that usually saves it from any heat exposure from the metal pipe going from the EGR cooler to the air intake, I am just going to push it up to avoid the rubber hose from getting any damage from rubbing on the EGR cooler.

 

Sweet !!!! Thanks !!!

 

Hey, you and @cnc97 are the Godfathers of this process

 

Or Evangelists.