I've kind of skip thought this thread fast, so pardon me if I'm redundant.
Was that the starter picture before or after rod broke?
Scope may or may not be revealing even if something had entered cylinder(s). I say this because hydrolocking doesn't necessarily leave marks in pistons, but metal object will.
On my first 4.7L starter job some years ago, I learned a lesson. I was taking my time and sent the starter and other stuff out to be rebuilt, so intake was off for weeks. I had each cylinder intake port covered or rather stuffed with paper towels to keep out foreign object. It was later winter going into spring and OAT was rising. As temperature climbed the coolant expanded. It began dripping onto head at #1 intake port from throttle body coolant hose, and ran along the length of the head from front to back ports. I didn't see (not in shop) for hours. When I did find the mess, I pulled out the wet paper towels. The ports, that had valves closed, where full of coolant. The ones with open valves filled cylinders. OH shHHHHIIIT! Well I was able to vacuum out the coolant. Added some Sea foam and vacuum it out, then oil vacuumed and more oil. Then once stater back in and all button up, I cranked engine with all plugs out, just to blow out oil or whatever was left.
So I can see how someone doing this a first time. May have easily gotten some coolant in cylinder #1, maybe even #3, then not even noticed. Fire it up and hydrolocked, bending the rod. This wouldn't leave any evidence of marks in cylinder. Then after running for a while, very rough probably, as crank now turning out of balance from unusual force of bent rod and finally rod just lets go as throttle opened to raise rpm clear up rough idle.
Very good chance you'll never know. So you've not much choice but move forward. But, to have a leg to stand on legal, you must give this shop chance to make right. If later evidence points to shop fault, well do what you feel is right. Accident happen!
Now issue at hand is get back on the road, with a reliable rig.
Engine or rebuild:
It may be just a few parts if cylinder walls & heads ok. A local shop I talked to, has replaced just a rod. They actually reused the rings and bearings. This was a 4.7 Tundra. 100K mile later still runs strong and doesn't use oil. This can be a lot of labor as engine must be pulled and pan. I didn't ask if he pulled head or crank but I'd assume just crank. This was done at request of client. Otherwise mechanic would have honed, replaced rings and bearing.
Engine Replacement:
You have a 2UZ-fe non VVTi made in japan. If you find a 100 series engine you can do a direct swap. If you go with a non 100 series engine the parts swapping is extensive, as you'll only use long block, front of engine and intake. But intake must be removed again to get off battery/starter wire harness. Which means a lot more labor. Note depending on year of 4.7L (98 - may 05) of 100 series engine used, none or some of your parts like throttle body will need swapping.
I just did a VVti , non 100 series engine replacement. VVT are hard to find and more expensive. My goal was to find an engine under 150K closer 100K the better. My first engine I got burned on. CL seller sold me one that had water entry into cylinders. The VVt is more inclined to get water entry, but all engine will if left in the weather or overly washed. So I got very particularly in my hunt. I also learned USA made 4.7L VVT have high incident of busted rods and heavy piston slap. So I stuck with engine made in Japan. I found so many scams & scume trying to sell me USA engine as JDMs, high mileage as low, engine that had been weathered or ones intake was remove and dirt fell in ports/cylinders. I found that; no JMS VVt have ever made it to the USA and only a very small handful of non VVT have every. One JDM seller assured me they had what I needed, but would not give picture I asked or VIN. After checking them out, I found, to be very shady. I ran carfax on every good prospect, most where BS.
I narrowed my search to Japanese made engine which is 100 series, GX470, 4runners. I also didn't want any bad frontal impact at high speed. Also engine must be protected from rain and snow. Which means front end intact, so side or rear impact was preferred.
I found one out of WI (rust belt not first choice) with 98K in a GX470, with perfect Lexus service history, new timing belt (old pulley & tensioner, WHY DO THEY DO THAT) no issue and a fresh total with hood & fenders intact. First thing I did this time was run my new borescope (plumber snake hooked to iphone via wifi for $30) down each cylinder. They looked great. Second was get oil pans off to look at and smell lower end, fan-freakin tastic! I had a good one.
If you look through my first link in my signture you'll find threads on engines.
Look through the Unicorns thread and you see overview disassembly, assemble swapping parts and install. With bunch of "while in there, let do it!
Scored a 2007 Unicorn. The holy grail of 100 series.
It's one sweet ride now.
Good luck and ask whatever you like.
