2010 prius high temp light

Got any warning lights/error codes? If you get a sucking sound when you open up coolant resevoir it's early stage of head gasket failure and you could get a year or two more before repair if you avoid long drives and the worst of the hot weather.

Also cleaning out the EGR system will help the engine run cooler.

 

air in cooling system?

 

Water pump not working or water pump is to the point where the impeller has cracked plastic on its coating It's rubbing the mag drive portion of the pump which is the well that the impeller turns in and it's working very erratically You can lower the coolant pull the pump off set it up on the car get in the car with the proper software you can call up the water pump and turn it on and you'll be able to see it chunking spinning stopping spinning stopping turning a little stopping turning a little stopping turn it off with the software turn the car off try and spin the pump with one finger It should go relatively smoothly

 

How many miles on the car?

What water pump and thermostat did you buy?

Posted via the PriusChat mobile app.

 

check your radiator with an IR temperature gun, cold or hot spots indicates a clog. Also check to see if your electronic fans are turning-on.
If anyone has ever put 'stop leak' or 'head gasket repair' into the coolant system - it's probably clogged and/or gummed up.

 

So you do not know the maintenance history for the car.

Is the engine in the car the original? Hopefully, a Gen 4 engine was not installed, because there are many reports of a Gen 4 engine overheating in a Gen 3 car.

Make sure that air can flow through the radiator. It could have sand, dirt, leaves, or debris in the radiator fins, which is not letting the full flow of air.

The previous owner(s) of the car may have had a bad head gasket and used stop leak in the engine coolant system. The original engine water pump may have been replaced with a cheap water pump. When you replace the water pump rotor, did you notice if "Toyota" was cast on the pump.

My guess is that reduced water flow is causing the overheating. This could be caused by restrictions inside the radiator (stop leak), or the water pump is not spinning fast enough. If you have ruled everything else out, I would buy a new OEM water pump and install it.

Posted via the PriusChat mobile app.

 

Replace that aftermarket pump with an OEM water pump purchased from a dealership.

Posted via the PriusChat mobile app.

 

The air bleeding procedure has been discussed already in this forum. Do a search to find it.

Posted via the PriusChat mobile app.

 

Man you are giving terrible advice.

The amazon waterpump is fine, its probably an Aisin pump which is the same as factory. Either way lets not just throw parts at the car dude.

Check the car for error codes first then report back. My car overheated ultimately because of a headgasket failure but intermittently due to using a stop leak that clogged up various parts, including radiator, overflow tank and thermostat.

CHECK FOR CODES WITH A SCANNER

 

So......now it is 13 days later......and it appears that the problem is not fixed.
But that should have been posted HERE instead of in a new thread.

This could be a simple as a failed pressure cap or a radiator clogged with dirt or bugs
in the external fins.

It sounds to me like it is time to let a shop test it and let you know what is wrong.

 

If your sure you have adequate coolant flow, Check the plastic coolant diverter valve; if so equipped and thermostat.
If it was me and you verified that everything above is working correctly; I'd go after the radiator itself; since you know stop leak was used. Partial clog, restricting coolant flow (effectively shrinking the size of the radiator from within)

That's what 'stop leak' does, coats the internal surfaces to plug a leak - much like 'slime' for tires

Sorry; That was Brian that mentioned stop leak in post #9.