JDM Engine in a US Prius?

It would interesting if you could describe the process to swap the engine
along with the time involved.

 

@Ragingfit 's video saga does pretty good at that. There are some extra wrinkles due to it being a 4th gen engine going in, but other'n that.

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

 

[QUOTE="Elektroingenieur”]the resulting vehicle might not be lawful to register or operate: replacing or reprogramming the power management control ECU would be emissions tampering, since it would change the configuration that Toyota tested and certified to U.S. and.[/QUOTE]

Good reason to change the laws, by all accounts you would be improving emissions.
Pathetic that it’s illegal to make an older car better in every way.

 

I found this on another forum. The INF codes that indicate where the issue is. I’d bet there is moisture in the AC compressor HV connector. If that’s the case, unplugging the connector and blowing it out would take care of it.


"The second INF code will indicate the area of the leak: 611 = AC compressor, 612 = Battery case, 613 = MG1 or MG2, 614 = inverter or DC cables, and 655 = MGR."

 

I'm in the first steps of the same install. Got a JDM engine from a place in FL, spent a little extra because it'd come with uncut wiring harness and such. Today I started on the job. The new engine looks great, practically new...it's going into a '13 V with 400k miles on it, ex courier vehicle.

So far I've cleaned the new engine's EGR cooler (used a HF 2.5L ultrasonic cleaner and Purple Power, full and then half strength)...it took a total of 10 minutes to remove the cooler and valve and 15 minutes to clean to brand new SS appearance. Swapped the spark plugs to the new hotter heat range that Toyota is spec'ing these days. Pulled the intake manifold to clean, but found it'd been broken at one of the airbox stud mounts, so I'll be using my old one which is surely completely plugged up with EGR crap.

Two things I've noticed so far.

My plan to reuse the practically new JDM harness isn't going to work. The harness goes to a vehicle that's wired differently. The off-engine end of the harness is different. So bummer.

The other thing is that just like the OP's, my new engine came with a smaller crankcase vent nipple on the valve cover than the one that's on the Prius V. I haven't looked at it close enough yet to see whether I'm going to swap valve covers or just modify the existing hose.

 

Yeah, I actually didn't mean that vacuum tube, I mistakenly thought the actual crankcase breather hose nipple that was built into the v/c was a different size. Whoops! I was wrong. Same size.

Today I had time to get the old engine out and now they're both sitting on my floor waiting for some parts to be swapped over. A few notes that stand out while I'm thinking of them...

1) Main differences in the two engines so far are: various wiring loom clip brackets that bolt to the valve cover, EGR valve, and maybe other places. Engine wiring harness. The short metal vacuum tube that bolts onto the transmission-end of the valve cover. I won't swap them, but the crank pulleys are different -- the US engine's pulley is grooved for a serpentine belt; the JDM's is smooth and is just a harmonic balancer.

2) I pulled the intake manifold, water pump, wiring harness, and tied the A/C compressor up against the radiator fan assy. Left hoses attached at whichever end would be easiest to reattach. I don't have a service manual and so am doing what appears necessary. I've read a few threads though.

3) I decided to leave the exhaust manifolds attached when pulling and installing these engines. There's actually tons of room around the windshield to pass the engine by...so much room that I didn't bother with cushioning the w/s edge at all. So all I did was pull the two spring-loaded bolts at the converter, and then I took a ratchet strap and pulled the entire exhaust system back about an inch so that the manifold would pass the exhaust system without touching as the engine was moved sideways away from the transmission.

4) The dowel pins holding the engine/trans together were good and tight. I ended up crawling underneath with a prybar and a small scissor jack under the oil pan to help keep things parallel as I separated the two. The trans is completely supported by mounts and doesn't need any help staying put when you pull the engine.

5) I didn't pull the EGR cooler when removing, to see if it was possible. I'd much rather have that entire little setup on and torqued before I install, and it looks like it's going to work. I've already cleaned it.

6) The most annoying part of the whole deal has been the million and one coolant hoses and wiring connectors, and Toyota definitely believes in stiff releases on their connectors. I've gone carefully and so far (knock on wood) nothing has broken, and all of the clips are good.

I'll update more later.

 

I stalled out for a couple hours here. Swapped the necessary parts over between engines, and while doing so I noticed that the engines had different color fuel injectors. My originals were blue and the new ones are tan. A closer look revealed different part numbers. The originals are 23250-37021, and the new engine's are 23250-37010. They're both made by Denso and appear the same otherwise.

So I paid a little closer attention to the v/c labels on the engines. The original engine says "X2ZR-W25N" and the new one says "X2ZR-W20N." Looking them up online says they're both hybrid engines, so I'm going back out there and hooking the new one to the crane and dropping it in. If I do have to swap injectors, it won't be a huge deal.

 

Runs and drives great! A little more info here for whoever might be looking for it one day.

-In addition to the other differences noted above, the JDM engine's flexible fuel line is a smaller diameter at the vehicle-hookup end. I replaced it with my original flexible line. The fuel rail was the same; I decided not to touch it.

-I cleaned the splines in my flywheel adapter and on the transmission's input shaft with brakleen on a rag. Then put a small bit of grease on the input shaft splines (there was old stiff factory grease there already). The engine slid together effortlessly.

-I also bought one of those Harbor Freight load leveler thingies for my engine crane and boy was that nice! Should have gotten one years ago. Excellent for precision alignment.

-On first startup, it sounded absolutely awful, jumping and bucking for about 5 seconds that felt like an eternity. I think it was air in the fuel system. After that, it smoothed out and every start thereafter was quiet and precise.

-I ended up replacing my intake manifold with a brand new one. Mine was completely plugged with EGR crap and I didn't think it was worth trying to clean immediately and reuse. I'll clean it at my leisure, if I can, and keep it for a spare. I have my original EGR tube in the ultrasonic cleaner now, and after about three 8 minute cycles it'll be completely clean. I'll do the EGR cooler next, then hang onto all of that stuff for 100k miles from now.

-Last thing I have to do is put it in maintenance mode and bleed the coolant. I thought it was good, had hot air coming out of the vents after a bit on the test drive, but the second test drive has no more hot air. Overflow tank is still a bit above the full line and I haven't gotten but about 1.2 gallons of coolant into it. Needs more like 1.5.

-I'd say this is one of the most straightforward engine replacements I've done. Doesn't really take very many tools, the fasteners are well-designed, and the layout is relatively well thought-out. The JDM engine needed very little to make it a clone of the US engine. The different fuel injectors seem not to be affecting anything at all so far.

 

Just an update on mine...

I've run a couple of tanks of fuel through it now, and it's getting about 41 mpg.

I'm still having some issues with the heat. I tried letting it idle for like a half hour or so in maintenance mode twice, and I still didn't have reliable heat. I'd get heat while in MM, but in normal driving, only barely lukewarm air. So I bit the bullet and bought one of the Uview Airlift tools P/N 550000 which came in today.

I'll give step by step on this, although it'll really only make sense to you if you already have one of these devices.

I drained all of the coolant through a fine screen-protected funnel and then into a 5-gallon bucket (I've got a lift here at my shop), then shut off the petcock. I had to use the rubber cone-shaped fitting on the Airlift. I used a little air-nailer type pancake compressor and vacuumed the system down to 25" in like 15 seconds....put the discharge hose into the top of my 5-gallon bucket in case any coolant came out (which very little did). Shut off the valve and disconnected the venturi line, then watched the vacuum gauge...it didn't budge for 5 minutes. Dumped a 3rd gallon of Toyota coolant into the 5-gallon bucket, then submerged the intake line completely to fill it, then shut the valve on it. Set the bucket on my tool cart so it was at about the level of the car's overflow tank. Pulled the valve end of it out (I had vise grips clamped to the suction end to keep it down at the bottom) and connected it to the main tool whose vacuum gauge still read a little over 25". Turned the tool's inlet valve on and then the intake line's valve on. It sucked coolant into the system as advertised, right down to 0" on the gauge. I let it sit for a bit to ensure vacuum was at zero, then removed it and capped the reservoir, which incidentally showed well over full.

I went for a drive and nearly immediately had heat, although it's not the amount of heat I'm used to in other vehicles. It's not "HOT"....more like nicely warm. I don't have a thermometer but I'd guess 80 degrees. I'm letting the car sit for now, seeing if it'll suck any more coolant into the system as it cools. I'll test drive it again and do the whole thing again if necessary.

I had a small amount of debris collect on the screen of the funnel which makes me wonder if the car has had Stop Leak put in it which might be clogging up the heater core. If so, I guess I'll have to pull the wiper and cowl assembly, remove the heater hoses and see if I can backflush them with a garden hose.

Maybe someone else can comment on whether the heat in these cars gets as hot as a 'normal' car when functioning properly.

 

I can tell you that my car will heat you out with the temperature set at 72 degrees on a 40 degree day.

 

5 years, temps to 10F, never any problem with heat other than waiting for the ICE to warm up the fluid to pass through the heater to heat the air. Just like any car. (I park in a garage, I pull out 5 seconds after I start the car, I drive gently at less than 30 MPH over gently rolling hills for the first mile, then accelerate to 55 going up a 400 foot hill. By that time, the heat is full on in any temp.

Invest in a infrared thermometer. Useful in cars (ever take your tires temps. Amazing what you can learn about alignment. Is the inside of the tire hotter than the outside?) Or house HVAC. I swear mine wasn't but $50 and has proved very useful. Point it at the vents. See what is coming out.

My memory was the lower vents never seemed terribly effective in warming the feet. Where the upper vents did work and the defrost definitely did.

 

I put a cheap thermometer in the vent on mine. AC Pro has one at most parts stores. I can get 160+ F at the vents with the temp maxed out and fan on low. Fan at high, the temp runs around 140. By comparison, the AC will cool to 36 F at the vent.

 

Did you find out why you do not have good heat? I had a Prius with the same problem. I had bled the system several times, also flushed the heater core. I could never find the problem. I ended up selling it out of frustration.

 

Did you had to swap the intake and exhaust manifold or damper assy from the old engine to work? I am thinking in buying a Jdm engine

 

On the 2016+ engine, the damper assy must be swapped. If the JDM assy is used, then the engine can be installed as is.

The basic key is this, if the engine sourced has the cast aluminum valve cover, it’s a bolt in swap. If it has the black plastic valve cover, at a minimum, the intake, exhaust, and damper must be reused from your existing engine.