Prius coolant temperature

Get an app called Torque for any smart phone. Use it with the Kwki OBDII Bluetooth adaptor or a ScangaugeII.

 

The above or just a Scangauge II. Either will give you coolant temp, or any OBDII reader that can display standard outputs. It's one of the standard outputs on the OBDII buss. These must be available in Finland, they are everywhere else.

 

I use a low tech approach. I have a cheep remote meat thermometer with the sensor epoxied to the outside of the power inverter under the hood with the readout under the center counsel.The power inverter is cooled directly from the radiator so you get the coolant temperature. It seems always to be 20 degrees f. above the outside temperature after the car has been running for a long time.

 

You're seeing inverter coolant temp., which is very different from engine coolant temp. And had better stay so! The inverter coolant part of the radiator is separate from the engine coolant part.

Engine coolant is allowed to warm up, and kept around 85C or 190F, by the thermostat and fans. Inverter coolant is kept as cool as possible.

 

What David is very true.....the engine coolant & the inverter coolant are completely separate.

 

What is the "healthy" range of the inverter coolant temp? And what would be too high?

 

You'd have to look up the semiconductors used in the inverter to get a definitive answer, but the general rule is if you can put your hand on it and hold it there it's fine. If it's too hot for your hand it's too hot for the semiconductors.
The hotter they run the shorter their life. Except when they reach a certain temperature they fail immediately. The actual temperature depends on the design (how close they are operated to their maximum ratings). I would be -very- worried if the inverter coolant was running above 80C and would expect imminent failure at 100C!

Do keep in mind inverter failure from normal operation is very rare. There were cases of inverter failure from cooling pump failure, so monitoring the temp. is probably a good idea.

 

Sounds good, I just added it to my Torque screen.

 

Check out the great graph created by Tim Bender in Post #301 in this thread;
2010 Prius Grill Blocking strategy | Page 16 | PriusChat

 

Thank you!