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

Coolant pump over revolution typically occurs when the impeller separates from the drive. The unloaded motor is free to rotate at a much faster RPM. In your case, I suppose this could be either a failed impeller or, if there’s a lot of air, over revolution due to no coolant in the pump.

 

Update. The temperature seems to be regulating, but I’m still getting the yellow car symbol with the “!” I reset that code and the cruise control works and the Energy monitor works. But after driving for about a minute that symbol comes back up and everything stops working again. What could be causing that?

 

Used the Gen 4 Water pump. Actually just replaced the thermostat housing but I didn’t pay attention to the jiggle pin. Right now it seems to be regulating temperature fine but if the light comes back on I’ll double check the jiggle pin. I did keep the overflow tank elevated. Fingers crossed that the temp stays good. Now I just need to figure out the other issues I’m having with the car symbol with the exclamation point

 

Thanks. There was a lot of air in the system so I’m leaning towards that as the engine I bought only has 12000 miles on it. Don’t seem to be getting that code after the dealer did the flush. Still trying to figure out the other issues now.

 

If you go back through the last few pages, there was a guy struggling with cooling and at one point i believe he drilled out the jiggle pin which seemed to fix it. But later found out that the placement of the pin had to be at 12 o'clock or it was useless. So that could very well be the issue.

That assumes the thermostat was moved during the housing replacement.

 

Just did another test drive and the temperature light came back on even though it’s not as consistent as it was earlier. Looks like I’m going to have to take the housing off and double check that jiggle pin.

 

Just looked at my original thermostat housing. There isn’t a jiggle pin. I replaced it with a Motorad 700-180 thermostat and it doesn’t have a jiggle pin either. Am I missing something?

 

Sorry about that. I didn't open my thermostat on either engine, so just went off of the info earlier in the thread. Assumed that was standard.

 

Page 23 seems to be where that info was. Assumed this was standard on all gen4 engines. Here's some of the info.

 

Ok. It looks like I literally have to take it out to see it. Thanks

 

Did you verify the new stat has that pin? I'd be 100% sure before opening it up. Remember I'm just learning and repeating info from here.

 

No I didn’t. I’ll go to auto zone and get one to look at before I take this one back out. I hate bleeding these cooling systems.

 

If you have a moment, can you take a pic of the t line leading to the reservoir?

Also Put your car on maintenance mode and check the radiator hoses if both large hoses are warm after the cooling fan turns on. If the passenger side is still cold then your thermostat is not opening resulting in air in the line.

 

Ok, I am halfway through this swap myself and I am now concerned about this jiggle pin.
I have a 2010, replacing the motor from a 2018, along with a new OEM 2018 water pump and new OEM 2018 thermostat. Am I supposed to do something with this thermostat's jiggle pin? I assumed I would just install the new water pump and new thermo and I would be set. I need to be sure before I install it and fill it with new coolant

 

Once again, I'm no expert, so if anyone more knowledgeable chimes in, take their advice. But my understanding is that it's as simple as making sure the pin is at 12 o'clock. I believe on the gen3 engine the stat only goes in one position so it's always correct, whereas the gen4 you need to line it up properly. That's what I'm recall from my research at least.

Gen4 water pump just mounts up like normal, no concerns there.

I didn't remove my stat during the swap and appear to have no cooling issues at all. As I sit here in maintenance mode running one last test.

 

Hey all, just completed my cold morning startup test and the car is running great! Noise is gone, cooling is working and engine is smooth. Just wanted to say thanks to everyone who shared info in here and helped along the way. Very much appreciated!

 

Can you briefly summarize what your concerns where, and what if anything resolved it? Sorry, too many blown head gasket threads, lol.

 

Sure, after completing my swap I had a horrendous noise whenever the ICE fired up that sounded like rod knock. Very loud clanking and banging, there's a clip of it on the previous page I believe. After a day of trouble shooting and testing it appeared to be coming from the damper, and mostly at low rpms with a surging at idle. The fix was simply driving the car hard for 20 minutes which appears to have either cleaned out something on the intake or exhaust side of things, I don't know exactly, and suspect at some point in time will rear it's ugly head again. But that's a different problem I'll worry about then. The actual engine swap itself went without issue following the guides and info here. This morning was simply a final test after letting the car sit overnight in freezing temps and it appears to be all good.

Couple things for future swappers....
- Flywheel Bolts: Use Red loctite, 36ft.lbs. + 90 degrees (14mm 12 point socket)
- Damper Bolts: 22ft.lbs.
- Motor Mount Bolts: 45ft.lbs.
- Engine to Transmission Bolts: 24ft.lbs.

Tools Needed
- 8,10,12,14mm sockets/wrenches/ratchets
- Several (many) extensions
- Highly recommend a battery powered ratchet
- Torque wrench
- E8 External Torx socket
- Long needle nose and bent needle nose pliers
- Also recommend an led strip headlamp
- Buy a proper fuel line disconnect tool

 

Yeah I had a vague recollection it was an "Italian Tune Up" that did the trick for you, but wasn't sure. It's a head gasket pandemic, hard to keep track of the patients, lol.

Did you have any trouble removing the existing flywheel bolts, assuming they have something like Red Loctite? I've heard it takes torching the bolts to loosen to soften that stuff enough.

 

*Also note, I purchased a fuel line disconnect too from Amazon...that did NOT work. I got my refund and they let me keep it..
Anyways I was able to use one from AutoZone with their Tool Loan program for free and it worked incredibly well!