2010 prius temp light comes on rarely

Your water pump is probably starting to fail If you had nothing to do on a weekend you could drain the coolant unbolt the water pump unbolt the impeller inside the water pump pull it out and match it up to pictures I could send you where the plastic wrap on the impeller is all cracking and fubar it barely can rotate and it's bore so when the pump is coming on it's never able to reach speeds it needs to to move the water to properly cool it or what have you I have pictures they're paying to post here It seems pretty standard for these electric water pumps to look like this internally You can feel the resistance and can imagine what applying power would do chunk chunk chunk barely able to turn and it's bore disastrous You can even plug the water pump back up to the car while you're holding it in your hand have your buddy start the car You can see the voltage and hear the pump feel it in your hand trying to run and it'll chunk chunk chunk. Good luck usually when this starts rather than doing a whole bunch of work You methodically do a few things at a time and inspections are key. Taking it to folks to work on it gets a whole lot of opinions with you eyeballs and a couple hands and you don't get to see any of it because their signs on the garage wall keeping you out I can't be kept in the dark like that so I mess with it at home in my driveway or whatever so I can see and know. Not be told any old thing by some kid in the service department.

 

What year engine was put in and from where?

 

Did those morons at the shop even LOOK to see if the fans were running ?
And to see if a "WalMart" plastic bag is stuck in the radiator ??

They did manage to suck a fair amount out of your wallet based only on a wild guess......on things that usually have nothing to do with over heating.

I agree that the most likely culprit is the water pump........but that is a wild guess too.

NOTE: ALL things that go bad and fail do NOT produce a trouble code right up front.

 

You can have all kinds of problems with the cooling system that won't necessarily set codes (until things get real bad).

I would inspect the car:

Is the radiator or A/C condenser fins clogged with dirt or leaf debris. Are the fins intact or are they corroded. I would run the car while monitoring the engine coolant temperature sensor. Does the ECT go up then "level off" when the thermostat opens - & at the correct temperature. What does it do at highway speeds. Do the radiator fans work. Does the heater put out hot air when it should. Does the car lose any coolant.

These are all "mechanical" tests that should be done to verify proper cooling function. Since overheat at high load can be an early indicator of head gasket failure, I would get the car hot, then pressure test the cooling system and leave it pressurized overnight. The next day I would pull the spark plugs and inspect the cylinders with a videoscope for any coolant.

Posted via the PriusChat mobile app.

 

First, go back to the dealership and get your money back.
They did NOT fix your problem.

Likely a water pump empeller. If you have techstream, or something similar, you can test
the water pump and see if it is working properly.

There is no inverter filter, there is no mas filter. You should ask them to show you those, and where
the are on the car. Then again, get your money back.

 

It's amazing how many dealers can replace or clean non-existent parts.

 

Service "managers" and "advisors" usually are NOT mechanics.
I put them right up there with used car salespersons.

In this case, what he told you was NOT necessarily right.
It depends on exactly HOW it fails.

 

One day when you're out fooling around with the car from a morning start up it doesn't have to be freezing cold but a first start You can actually put your hand on the water pump believe it or not and feel the motor running If you can afford to borrow tech for a few minutes you can see the water pump RPMs on a screen then you can run the water pump in tech the Toyota software and make it go fast and slow and on a funky water pump with the impeller plastic cracking and all that when you try to speed the water pump up if your hand is on it while you're doing this you can feel the pieces of plastic rubbing on the bore it dpons in feels like an unbalanced thing spinning . Then when you remove the water pump undo the extra 4 bolts on the back side and lift the rotor or impeller out of its bore and you see all this damage then you stick it back in said before and you try to turn it by hand and realize you need a small pair of pliers you realize the trouble the electricity is having making all this work. Then when you get a new pump before you bolt it all up you can plug it in lay it on the frame rail or have your assistant start the car and see the water pump spinning then again you can hook up tech make it spin fast and slow and you will hear feel and see the difference so you'll never have to see it again.

 

A problem with Priuschat advice is everyone assumes the op has all the tools, scanners and experience needed to diy. In this case "wild guess" was the closest to useful info since no one went with a clogged radiator. Radiators are rarely a problem if the proper coolant had been used and no head gasket sealer had been added in the past. Guessing based on past experience sometimes works - its a probability game.

A new short block (see diagram below) from a dealer generally includes a rebuilt head, complete gasket set and cleaning of other parts. Its an engine out job and is as close to a new engine you can get. I imagine that cost $5k-$8k and should have eliminated oil burning.

Essentially you have a 96k mile engine which should be good for another 100k miles if the recent overheating did not get severe. I use a $35 P10 scanner (link here) to watch my coolant temp.





New Genuine Toyota Short Block 1.8L 2ZRFXE with crank & pistons assembled from factory:


Short block is at least $2100 for the assembly alone.

 

The short block does not include the head. The long block does...

 

But the dealer will rebuild the head

 

Okay, But a short block still does not include the head.
And if the are going to rebuild it, it's probably cheaper to just get the long block.
So less labor, and time, and possibly screwing up the timing chain....

And if the head is not warped, no extra money spent.

 

How long should an OEM water pump last?