Temp warning light turned on, turned off, then check hybrid system and engine lights turned on

No, the car will shut down on you without notice, this is very dangerous.

The car already told you what the problem is, the engine waterpump not the inverter waterpump. Order now it is an easy replacement.

Posted via the PriusChat mobile app.

 

That sounds good if head gasket blown would look like a milkshake so you may be just water pump. It will not be transparent/

After pump replacement keep an eye on the engine temp for a while. And get after the egr cleaning its way over due.

here's another poster:

Not Your Typical EGR Problem, New Member | PriusChat

 

3rd gen engine coolant capacity spec is just under 2 gallons. So even if you do a very complete drain you'd be ok with 2. A lot just drain the rad, likely drain just over a gallon. Repair Manual advises to drain the block too, but not sure how much you get there: I've heard just a few tablespoons. Pulling off lowest exhaust heat recovery hose I've heard can get you almost a quart.

Watch @NutzAboutBolts video, and I can post Repair Manual info in a bit.

 

Info:

 

When you remove the water pump, you'll lose coolant. Check the hoses and make sure they are good.

 

Don't do the inverter? Just thinking to do them one at a time, just in case something crops up.

Also initial inverter coolant change in states is 15 years or 150k miles.

 

Ray you suggest that at 139,000 I should get the water pump replaced in my 2010 Prius hybrid?

 

For future lurkers:

I know that pump will last twice as long if you get that initial break in coolant out of there. On my G2 I dumped the engine coolant at 50,000 miles I learned a hard lesson don't that on a G2 as it was really hard on to get the air out.

Best and easiest way to change the coolant is just dump the radiator itself. It will really help and not invoke any air lock. Then dump it again in a few months.Its not all the fluid alot more in the engine but will really help without the hassle of a 100% dump.

Just open the rad cap open the rad petcock drain on the bottom let it all drain out in a tub then close the petcock fill it up with new coolant put the cap back on and drive away. The next morning when car is cool open the rad cap again to see if the coolant moved around a little and top it off.
Do it again in a few months. The fluid will look really good after 2 of these and no air lock no hassle.

Really helps extend the life of the cooling components. Its that initial first 50,000 miles that's really hard on all the fluids.

Especially the trans.

 

I am the preventative maintenance type, so I would.

The coolant loop in the Gen3 is easy to bleed the air out of.

The cost of the pump is high though.

Worth it for piece of mind to me.