2013 Prius V overheating, using coolant

How many miles?

There is a very good possibility that the engine water pump is bad. To confirm, you need a scanner that can read the engine coolant temperature and water pump speed.

 

Any unusual engine shake/noise during cold-starts?

 

No observable leaks could mean the cooling system is not moving coolant or is clogged up with stop leak and is causing the reservoir cap to release.

OR

The head gasket is blown causing coolant to be burned. Symptoms include occasional severe rattling at engine startups (actual engine start not just Ready). If severe rattling happens and then clears it is almost always a head gasket. Eventually loss of coolant causes overheating and reservoir releases.

Testing

Filling the system is essential before testing.

Some codes may be present and can help determine the scenario. Head gasket problems may not code for weeks or months.

Monitoring both coolant temps with a scanner like Techstream or an app like Car Scanner can help diagnose the first scenario.

Running a borescope test is good for the second scenario. This should be done with the engine cold and the cooling system manually pressurized.

After warmup water flow can be seen here


If the coolant overheats, this pressure cap releases coolant



Techstream scanner with both Coolant Temps, one in Combination Meter ecu


Car Scanner App and bluetooth adapter


Two coolant temps on engine

 

This’d be good to know.

 

The P148F code description is "Engine Coolant Pump Over Revolution ". Replace the engine water pump with a Toyota OEM pump ASAP. That should fix the problem. Also, use new coolant when you fill it back up.

I copied this from a 2019 post made by ChapmanF, "P148F means the water pump motor was spinning too fast, which means, for one reason or another, it wasn't pumping water. Either the impeller in the pump had broken, or there had been coolant lost and the pump was spinning in air."

I recommend the Autel Maxi AP200 scanner. It costs about $60 on Amazon. Take a look at this thread,https://priuschat.com/index.php?posts/3248209

 

"Maybe" foolhardy, but if-and-when, I'm going with Aisin WPT-190, ostensibly what the Toyota pump is. iF you don't get stung with a counterfeit. Likely through Amayama; never had a problem with them.



For me, Canadian funds, the Aisin is $131.53+$37.03=$168.56, all-in, which converts to $123 USD (0.73 exchange rate)

The price of the OEM through UAE (United Arab Emirates) might be elevated currently, due to war, not sure. Current suggested list price through Toyota USA Parts is $367,74 USD, and checking "street price" a nearby-to-me US dealership: $276.35

 

Not really. The key is to fill the reservoir tank very slowly so the air can escape during filling. Fill the coolant to the "B" line on the plastic reservoir, which is the line higher than the full line. Then drive the car. Air will self bleed out of the cooling system. After the coolant cools down (like sitting overnight), the coolant level should drop down to the full line.

 

Please take a few pictures of the old water pump and upload them for us to look at.

 

That “might” work, but it’s not what Toyota recommends, the repair manual guidance is to run the car, stationary, in maintenance mode, till coolant is fully warmed up.

Regarding "fully warmed up", second time changing the coolant, I "thought" it was fully warmed, shut off off the car after a protracted run-time in maintenance mode, crawled under to replace the engine shield, and noticed the accessible coolant hoses there were still stone-cold. So I restarted the car in maintenance mode, crawled back under, and kept checking the hoses. Another 5~10 minutes, they finally got hot, presumably when the thermostat finally opened.

Attached engine coolant change excerpt from repair manual has the maintenance mode instruction (tacked-on, at the end, from another part of the repair manual), but it's poorly presented, buried in various other "modes" and techstream methods. A more colloquial summary:

====
MAINTENANCE MODE:

Perform the follows steps in less than 60 seconds. Begin with the car completely off.

1. Set the parking brake.
2. With foot OFF the brake pedal, press Power Button twice.
3. Fully depress gas pedal twice.
4. Depress brake pedal and and shift to Neutral.
5. Fully depress the gas pedal twice.
6. Push Park button.
8. Fully depress the accelerator twice.
9. Check that "Maintenance Mode" is displayed in the multi-information display.
10. Step on the brake pedal and then press the Power Button to start the engine.

To cancel MAINTENANCE MODE, turn off the car (by pushing Power Button)

Important: DO NOT drive the car in maintenance mode
====

 

I have changed my coolant at least ten times. No need for maintenance mode and waiting 45 minutes for the thermostat to open.

If your time is worth something just drive it ten minutes which will warm it up quick and open the thermostat, which is the goal.

You can see flow in the reservoir as shown above when the thermostat opens.

It's not even necessary to have the heat on as some flow always goes through there as well. However you can tell when the engine is warmed up by a lot of heat from the heater.

 

Attachment to post 16 has the repair manual instruction. One exception I'd make: don't bother with the engine block drain (maybe not mentioned in later editions?); there's at most a quarter cup drained there.

And your call re using maintenance mode, I have, but others haven't, successfully, and I know Toyota is prone to overkill. Live an' learn.

It's basically: drain from the radiator spigot, close it, refill reservoir to B line, drive.

From my notes: see I managed to drain 4.25 liters, so looks like you'd need to purchase a couple of US quarts