No regrets man. I admire the courage, time and financial investment you put in to this project that no one was willing to tackle.
I do believe I have found the root cause. 12 lbs of compression on Cylinder 1. 2-4 have 180+ by comparison. I think one of the valves on exhaust side got hit when the piston came apart. I get to rip the engine out again. I am going to hit the local pull a part and see if they have any Vibe/Matrix/Yaris cars in inventory. Since the engine designation in those is 2ZR-FE, with the difference being the variable intake timing, I’m hoping I can get a usable head that way. If you price a Prius head, you pay a Prius price around here. But a Yaris/Matrix/Vibe is peanuts in comparison. One thing I did note though in my compression testing. Disconnect injectors and coils, just put it in ready mode and hit the gas. LoL.
Done. Bad valve is on the left. Number 1 intake valve. Luckily I had an entire head to scavenge part from.
I was going to ask you if the valves were the same on Gen 3 and 4. I take it they are! That kept you from spending extra money! Did you check the exhaust valve also? It was in the back of my mind when you showed that you had a broken piston for #1. And also if you were going to seat in the valves and replace the seals since you had the head off. Seems you should be good to go once you get it back together. I'm glad your hard work in paying off!
First drive and it is running better then when I got it. No hesitation on hitting the gas and the ICE starting. Pretty racy for a 61 mpg car. LoL
This thread should be a warning/advice to anyone thinking about putting a Gen 4 engine into a Gen 3 car. I’m going to sum it up this way. DON’T DO IT!!! LoL
The bent valve was in the Gen 3 head that I reused do to the differences between the Gen 3 and 4 heads with water outlet locations. But I scavenged the valve from the Gen 4 head. I do have to put the Gen 3 oil dipstick tube on though. Or the air intake flex tube and silencer don’t fit. It has a little induction noise at WOT now. Similar to flipping the top of the older car air cleaner tops. Very noticeable inside the car when driving.
Twenty five miles in and not an issue at all. So I filled it with gasoline and drove across town. Here is the trip summary. I’d say that the car is running better then ever.
The Gen IV was supposed to have reduced friction in the motor, maybe if nothing else you will get better gas mpgs. Quite an achievement
So I’m 150 miles post engine install. Oil is still full, coolant is still full. I did change the oil dipstick tube to allow the last part of airbox to be installed. Gen 4 dipstick bolts to right most casting hole on engine block. Gen 3 dipstick tube bolts to inner casting hole. Tubes and dipsticks are the same, just attach differently. Easily holding at 60 mpg in normal mode. If I’m not watching instant economy meter next to speed, it’s nearly impossible to know if the ICE is running or not.
A few years ago, I junked a decent vehicle that had a similar type of catastrophic engine failure. I have been kicking myself in the behind ever since. Now I feel vindicated by having “grabbed this bull by the horns”, so to speak. There is a 2012 Prius V near me that has a blown engine that I half way thought of picking up and giving it the same treatment. But this has drained my disposable income for a bit.
That "money" factor will get ya every time! I hate wasting stuff. I like fixing things and if I can extent the life of something, I will. I wished I had the money to fix up another Prius. My 78 Corolla was extremely easy to work on. And the Prius so far has been also.
Dear cnc97 I want to thank you for taking the time to document your experience for all of us. My 2010 is now nearing 250K with no problems other than wheel bearings. A year or so I after I purchased it I picked up a complete engine and transaxle with less than 5K miles on it. My hope is the original engine will last till 500K, but having the spare assembly sitting in the shop covered is insurance in case something happens. A bummer that the subtle differences between the Gen3 and Gen4 ruined your plans for an easy swap, but I appreciate you letting us follow your progress. I hope your work pays off and gives you many more miles of prius reliability.
250 miles post install. Took it out the highway. Cruise at 60, AC on Auto set at 74. It did drop back to 59 mpg on the return trip. Cruise at 62, sunroof open and drivers window halfway down.