2011 toyota Prius overheating

you most likely have an air buble in the system. you need to ensure you bleed the system properly.

 

With many available ways of connecting to the car's diagnostic port (Toyota Techstream on a laptop is one way, but there are also a lot of phone apps and such), you can watch the engine coolant temperature while the engine is warming up. That could help us a lot with determining what is going on.

The Gen 3 engine has two different coolant temperature sensors (in this post you can see a phone app displaying them both, as "Temperature_7C0" and "Temp_7C4"). One of them is right at the coolant outlet from the cylinder head, and the other measures the coolant returning from the exhaust heat recovery system. (That is coolant that has come out of the cylinder head, right where the first sensor is, but then passed through the cabin heater core, which normally cools it down some, and then passed through the EHRS, which normally heats it back up some.)

If you're using Techstream, you see the cylinder head sensor reading on the "engine and ECT" screen, and the EHRS return temperature on the "combination meter" screen; weirdish, but that's the way the car's wired.

 

Chap:
Good information there but I think you might be overlooking the "obvious".
Water pumps are a common failure item on these cars often due to fractured plastic impellers.

 

Not too surprising that there can be more than one component that can cause a failure.
Glad you figured it out.

 

Have you had the car since new? Just wondering if someone might have added a head gasket stop-leak product to the "equation". The EGR and intake's cleaned?

 

Nah, that was by choice. I'm aware of the fractured-impeller issues and the swelling issues (I've reposted pictures of them several times), but my preference is to encourage the owner to collect the easy facts that will support the diagnosis before turning any wrenches, and I like to encourage doing that while the owner is not yet biased by hearing too much about what my guesses might be. Chances are, if the pump is the problem, the easy information gathering will show pretty clearly that's the issue, and then the wrenches can come out, with a known problem to solve.

People's circumstances are different, and if the owner ends up saying "no, I haven't got anything to gather that information with", then there's always the option of just taking stuff apart and looking, and trying to do that with the most likely suspects first. But when you have a way to do it, gathering the information up front is so easy and takes so little time, and gets no grease under your fingernails, that it's just a very valuable habit to get into.

Yeah, I've seen some pictures of that too. You can probably distinguish the cases by the code that may be set; a swollen rubbing one will probably set P261B for rpm too low, while one with the impeller busted off may set P148F for rpm too high, in the later years that have that code.

Practically speaking, the rotor/impeller is kind of one inseparable ... thing ... anyway (though it seems to be made in a few pieces and glued or plastic-welded). Just sits there on its fixed shaft and spins when the "motor" gins up a spinning magnetic field around it.

 

If the spinning bit was made out of some metal, would that mess up the magnetic propulsion? I'm just wondering why it's made outa (problematic) plastic.

 

i'm guessing they thought they were making it outa non-problematic plastic. Not sure if the materials engineers goofed on the specific resin they chose and compatibility with SLLC, or some of these cars haven't stuck with SLLC, or what.

The impeller being two pieces glued together, as it appears to be, seems maybe worth revising. Probably a shape they weren't able to make in one piece, but with developments in manufacturing technologies, maybe that's just not yet.