New Engine, New problems: need some direction

Hey folks! Y'all have been tremendously helpful to me in the past so I thought I'd call on you again.

Last year with some guidance from you fine folks I replaced the head gasket in my 2011 Prius IV. It went great, but I guess she was just too far gone because a few hundred miles later I threw a rod.

I bought another engine and started the job of swapping them out -- got the old one out, but the stars didn't align for me to keep working on it for nearly a year. We finally got the new one in and all the parts back on, new oil and coolant. Put it in maintenance mode successfully, started it and...

Well, it ran perfectly for about 10 seconds, then shut off and threw me a yellow triangle and a check hybrid system warning. Now the ICE won't start, in normal or maintenance mode. It comes on, I can hear stuff in the inverter area spinning and clicking, but no ICE.

I had to scoot off to work so I haven't even had a chance to check codes, just trying to think if there's something obvious to pursue here. My thoughts:

1. Could the hybrid battery be toast from being parked so long? I had the safety plug out and the 12v disconnected (had to replace 12v bc it wouldn't charge) but a year is a long time. I would think that the engine wouldn't have cranked the first start if the hybrid battery was dead but idk.
2. Bad gas? Has it been long enough for the gasoline to go bad?

I have no idea where my code reader is so I won't be able to check codes til tomorrow at least, and I'll update with that info when I have it, just trying to get an idea of where to head next for this job.

 

Bet, I'll give that a shot and let you know

 

EGR and intake are clean, didn't replace water pump however. I'm not sure if we swapped the water pump from the old engine to the new one, but i don't think so.

We bought the replacement engine used, so it could have had some issues we weren't told about. Everything looked solid visually though, and when I drained the oil it wasn't gunked up with coolant or anything like that.

Gas tank is half full so I'm not sure adding fuel will help, unless my suspicion that the gas has gone off is accurate. Should I try siphoning the old fuel out and refreshing it?

 

Updates!

Checked codes:
P0118 (i had failed to plug in a temp sensor, d'oh! resolved)
P3191
P3190
P0403

I added gas as per @JC91006 suggestion. Car will run for longer now but sounds rough -- might need to go through and clean these EGR parts again, just to be sure. No milky oil or stinky coolant or other head gasket symptoms at this point. I've got parts from 2 different engines I can swap out and see what's in the best condition.

However now, after running for about 30 seconds to 1 minute, I get a Low Traction Battery warning on the display telling me to shift car into Park (it's already in park). Sometimes it'll shut off the ICE at this point, sometimes it won't. Thoughts?

My biggest fear of course is that I'm gonna have to buy a new hybrid battery. Tbh it's worth it to me at this point to replace it rather than trying to unload this scrap heap and buy a new one, but I don't want to invest in that until I'm reasonably certain that everything else is fine

 

I haven't taken it out of the garage yet. My driveway's on a steep hill and I'm scared of not being able to get back up it. The 12v battery is brand new, the old one was dead and wouldn't charge. I'll see if she'll... pull out of the garage and back into it, just to give it a chance to run in drive and make sure it's shifting properly?

 

Attempt to force-charge HV battery didn't go super well. Battery meter looks almost full when I start the car, then drops to 1 bar very quickly. I am able to shift into drive, and the engine is sounding smoother now when i press the accelerator, but it instantly throws up the warning that I need to put the car in park. The battery doesnt seem to be charging when I press the accelerator, and it will eventually throw the "Check Hybrid System" warning, at which point the engine will no longer start until I clear the codes. I attempted this twice, and the second time the engine continued to run without going to "check hybrid system" (though it did tell me to switch to park), but after a minute or two I saw smoke creeping out from the exhaust manifold area so I cut it off.

There's a burnt smell coming from that area now, but it's not that foul smell I experienced with the head gasket leak. Coolant is stable. I'm just obsessively checking for head gasket/egr symptoms since we've already been to that particular circus lol.

 

Agreed, I'm not gonna be able to mess with this til next week so I'm gonna disconnect the 12v and do some research. Plan of action is to take apart the EGR system and give everything a good cleaning. Make sure I've got the best of both sets of parts in there and see if that handles the rough idle/smoking issue. If I can get it running smoothly enough to recharge the battery we'll see if that keeps acting funny.

That seems above my pay grade to replace, but I might ask around local mechanics and see if someone will swap one for me for less than one of these little mobile battery dealers, if this one turns out to be shot

 

OKAY SO it's been a minute but I want to update on this. I love this car dearly and am about to yeet it into the sun.

Got in there to check on all the EGR parts and everything looks pristine. Well, not PRISTINE, but reasonably clean, we had cleaned the EGR before the engine replacement, and basically chose the better parts from the two engine assemblies to put back together. I followed my hunch about the gas, hooked up the fuel pump to a 12v battery and drained every drop of gas I could from the tank, filled it back up with premium gas.

Ran perfect after that.

No funny noises, no codes, no drama with the hybrid battery, put a few hundred miles on it over the next week with no issues whatsoever.

Until.

I went to check the fluids before a long drive and noticed my coolant reservoir was low. I immediately panicked, but then realized I didn't burp the coolant after refilling it when we put in the new engine. So I filled it back up, and got a small shudder when I started her up. Like, half a second, but I Know that sound. Drove it a little bit, shudder didn't repeat, no codes or misfires per my code reader, but i Know that sound.

Did long drive bc I didnt really have a choice, lost maybe another quart of coolant in the process. I have not experienced any major engine shake, overheating, no CEL and no codes, but I am experiencing coolant loss and a barely-perceptible shudder/hesitation on cold start and twice when making a sharp turn.

Could this be because I didn't properly "burp" the coolant when I added it? I'm going to change the oil tomorrow to see if it's all milky, though it looks clean on the dipstick/oil cap. Is there anything this could be other than the head gasket? If it's head gasket again I am walking into the sea lmao

Water pump maybe? Am I possibly overreacting? I dont even know anymore y'all my brain has been mostly replaced with cuss words because of this vehicle lol