Radiator is cold...

Which tank are you checking, is it the one at the very front of the car or the one between the engine and inverter box.

 

Have you had any coolant service done recently? It is not normal to hear any bubbling or coolant circulating through the dashboard, as you state. There could be air in the system due to a leak (look for pink crust, especially at the water pump)or improper bleeding. Absent that, the thermostat may be stuck open.

 

...I believe the sound of liquid gurgling is a symptom of having air trapped in your system. I keep wondering if I have air in there too, even though as you say the appearance is full. I am not the expert but you may want to run the car a while with the cap off and see if level fluctuates. In any case, getting air pocket in your antifreeze is common Gen2 Prius issue.

 

You also need to check that the thermostat is working just as in all other cars.

JeffD

 

You have air in the engine coolant system. Was the coolant replaced at some point in the past?

1) Remove the large black plastic cover over the radiator (held on with six plastic fasteners) for access to the radiator cap. To remove a fastener, rotate it with a Phillips-head screwdriver while exerting upwards pressure on the cover. The fastener will pop out of the hole. Remove the cap and see where the fluid level is.

2) If the fluid level is low, top off with Toyota Super Long Life Coolant. Do not use a lesser substitute. Replace the radiator cap.

3) Once the fluid level is correct, start the Prius. Turn on the heater, set temp to MAX HEAT and the ventilation fan to max speed. Rev up the engine repeatedly to 3,000 RPM or more - may take 5-10 minutes or more, while listening to the air bubbling in the heater core. Keep revving up the engine until you no longer hear bubbling.

4) Turn off the Prius. Feel the radiator cap. If it is not very hot, open the cap, check the radiator fluid level and replenish to top of radiator neck as needed. Otherwise wait for the cap to cool down, then check the fluid level and fill. Replace the black plastic cover and you are done.

 

That is not the tank for the engine that is the coolant for the inverter and transmission. The tank you want is under the black plastic cover right at the front of the car as explained in the above posts.

 

Since you are well passed the 100,000 mile marker the coolant should be replaced every 50,000 miles with the correct coolant Toyota SLLC. It is likely however that the engine coolant pump is leaking and will need to be changed changing the fluid at the same time. However the fluid will need topping up now.

 

Please check the engine water pump for leaks as topping up will need to be done often otherwise and if the pump is leaking it can only be a matter of time before it's bearing fails completely maybe stranding you somewhere.

A leak at the pump usually shows up as a red crusty deposit inside the water pump pulley and sometimes as a line on the underside of the hood.

John (Britprius).

 

I am thinking there are two filler caps, one for the radiator itself, which when open you are looking straight into the radiator fluid level, and the plastic overflow pot, which has the bends. The most direct way to refill (at least what I do) is pour straight into the radiator until full to the top. Then I also fill the overflow pot to make sure there is some extra if needed. I do not take the black plastic off, I just reach under there to unscrew the cap. Loosen one screw maybe.

 

You were probably filling the reservoir tank rather than the radiator. If it's really cold, like in the twenties, the prius thermostat will never open and hot water will never circulate through the radiator. The only time water circulates through the radiator is when the thermostat opens which only happens when the water in the core, behind the thermostat gets hot enough.

Secondly, the heater has *nothing* to do with defrosting your windshield. Your AC is what does that, so if your defroster is no longer working, then your AC is shot. You can keep the temp output to 65 (minimum) and if your defroster is working, it will clear the windshield in seconds.

 

Seriously?