Greetings Prius owners. I do not currently own a Prius, but I have crash tested a few. Does anybody know what this tank does? It is called a 'Coolant Recovery Tank' in the assembly drawings. But what is the thing trying to cool? It costs well over $1000 to purchase and has warning stickers on it too. Is it full of toxins or something? Any and all help greatly appreciated.
Its the cars thermos to keep a nice cup of joe warm for those cold start ups. It can keep the coolant warm for many hours even in cold temperatures.
It is full of Toyota Super Long Life Coolant, which is as toxic as any other automotive antifreeze. The warning stickers are primarily because the fluid will be relatively hot compared to coolant elsewhere in the engine coolant loop. The point of the canister is to allow warm coolant to be circulated to the engine upon first startup. This reduces the warmup cycle time and minimizes engine emissions during that period.
Thanks guys. So, does it just keep already hot coolant hot (thermos) or does it have a heating element to warm the coolant prior to start up?
It just keeps already hot coolant hot. When you shut the car down you'll hear an electric pump for roughly 15-20 or so pumping hot coolant into this tank. When turning the vehicle back on, it will pump this coolant back into the engine to assist in warm-up.
Wow, indeed! It should make you a latte for that much scratch. Are you sure it is engine coolant and not coolant for the inverter/convertor, assuming that it has coolant? I guess I don't see the benefit of keeping your engine coolant warm while you are in the store shopping for 1/2 an hour. I mean, why wouldn't a normal car have something similar?
My understanding of the benefit is that emissions are reduced on cold starts. "Normal" cars don't have such a thing because the Prius was engineered to minimise pollution.
Yes, the thermos is for engine coolant. The inverter/transaxle also has a separate coolant loop. The thermos does not greatly help a restart 30 minutes later. The benefit comes from starting the car in the morning, after an overnight shutdown. A normal car is not trying to achieve AT-PZEV status. The thermos can be found only in North American Prius.
It seems to be in a vulnerable position there on the car.. one minor corner hit and kerpsplatt!! As for North America only.. well my UK one has one too.. I hear the pump whirring away after the ICE shuts off.
Is it possible that you are hearing the brake pressure accumulator pump? If you repeatedly press the brake pedal when the car is READY, that will force the pump to run. If you are motivated to look for the coolant heat recovery canister, it is hidden behind the LF fender liner.
In the UK, the sound comes from the Lucas electrical system. With Lucas, they have to use an electron bilge pump to removed spilled charge from the cabin floor, otherwise it gets too high and shocks the occupants. Tom
Crashman, how do you think the Prius really stacks up with other makes in the crash tests? That must be an interesting job. GT
