Water Pump - Is It Electric?

[Vlad Soare]

Hello,

 

I've recently noticed something strange. The ICE had stopped, the car was in EV mode, and yet the water temperature gauge kept rising slightly. How come? Is the water pump electric?

 

Thank you.

 

 

[murphy]

It has to be electric. It's the same engine that is in an Energi which can go over 21 miles without the engine starting.

[ptjones]

Hello,

 

I've recently noticed something strange. The ICE had stopped, the car was in EV mode, and yet the water temperature gauge kept rising slightly. How come? Is the water pump electric?

 

Thank you.

 

 

No it's not electric, trans cooler is on the Energi Fusion/CMAX models. Temperature rises because hot water rises to the top of the cylinder head where the WT gauge is. You will notice the WT goes down when the ICE starts running again. :)

 

Paul

[billford]

Hello,

 

I've recently noticed something strange. The ICE had stopped, the car was in EV mode, and yet the water temperature gauge kept rising slightly. How come? Is the water pump electric?

 

Thank you.

 

 

 

Water pump is electric, mounted beside the oil filter.

The temp gauge will vary.

This engine is pretty well impossible to overheat. If you ignore the dashboard warnings, it will go into failsafe cooling. 2 cylinders will be disabled and it will run on the other 2 cylinders. The idea is to get air pumping through the disabled cylinders to cool down the engine. If the temperature keeps rising, the engine just shuts down to protect itself.

[Vlad Soare]

Thank you.

My observation aside, I was thinking that an electric water pump would also make sense from another point of view. When it's cold outside and you turn on the cabin heating, the water pump must be running, because otherwise the water inside the heater core would cool down almost immediately. So, even if the ICE were warm enough, and there were plenty of hot water in the circuit, the ICE would still have to be kept running just to refresh the water in the heater core. Whereas an electric water pump would take care of this by itself without any help from the ICE.

Edited April 30, 2017 by Vlad Soare

[ptjones]

I checked in the service manual and it is electric, but I haven't found any info whether it's running when ICE is off. ;( I know how to figure it out, I use ICE block heater and if I start out in the morning in EV , I can watch WT to see if it changes much when driving using my ScanGaugeII. :) I do know that when the ICE starts the WT goes down.

 

Paul

[ptjones]

I have the car up on jack stands with power on and there is a humming sound coming from the area of water pump although I don't feel any vibrations. I will be doing more testing.

 

Paul

[ptjones]

Just came back from trip using A/C which means radiator fan is running and it is very obvious that water pump shuts off when ICE does when watching WT. When ICE turns on the WT drops 5-7 *F in 20 sec. :)

 

Paul

[Vlad Soare]

So, the water pump is electric, but under normal circumstances it only runs while the ICE is running.

If it's electric, then I guess it could theoretically run with the ICE off under certain conditions. I can imagine a couple of situations when this would make sense.

Edited May 13, 2017 by Vlad Soare

[ptjones]

So, the water pump is electric, but under normal circumstances it only runs while the ICE is running.

If it's electric, then I guess it could theoretically run with the ICE off under certain conditions. I can imagine a couple of situations when this would make sense.

I agree with you too. But with the 12volt problem they may not want to have anything running after the car is shut off. It might hurt MPG's if ICE isn't running and they don't seem to be to concerned about the ICE getting hot when you don't get over heating alarm until 246*F WT. Heat loss is wasted energy. ;( Without Grill Covers it would be hard to get the ICE very hot without something going wrong like leaking coolant. ;(

 

Paul

 

PS I have noticed the only time the Radiator Fan runs is when the A/C is on. WT can be 220*F and no fan.

Edited May 13, 2017 by ptjones

[Vlad Soare]

I'm not saying it should run after the car is shut off. I'm thinking about the car being turned on, but with the ICE off. This would not cause any problems with the 12V battery.

 

One possible situation would be when the radiator fan weren't working properly (say, due to a burnt out fuse, or a faulty relay). This is by no means an unlikely event, as I've had it happen before in several cars. In that case the engine would heat up much faster than the water could cool it down. So it would make perfect sense to shut the engine down but keep the water pump running. Eventually the water will cool down. Of course it will cool down much slower than if the fan were working properly, but it will nevertheless cool down eventually, provided the engine doesn't produce any fresh heat.

 

Another situation is in winter, when the cabin heating is on. In winter, even if the high speed battery is full, the engine is still required to run from time to time just to heat the water, to get warm air inside the car. When the water is warm enough the engine stops. But the water inside the heater core will cool down almost immediately, so the engine will have to be started again, even though the rest of the water in the circuit is still warm enough. Wouldn't it make sense to use just the water pump to bring fresh warm water into the heater core, without starting the engine?

Edited May 14, 2017 by Vlad Soare

[ptjones]

I'm not saying it should run after the car is shut off. I'm thinking about the car being turned on, but with the ICE off. This would not cause any problems with the 12V battery.

 

One possible situation would be when the radiator fan weren't working properly (say, due to a burnt out fuse, or a faulty relay). This is by no means an unlikely event, as I've had it happen before in several cars. In that case the engine would heat up much faster than the water could cool it down. So it would make perfect sense to shut the engine down but keep the water pump running. Eventually the water will cool down. Of course it will cool down much slower than if the fan were working properly, but it will nevertheless cool down eventually, provided the engine doesn't produce any fresh heat. ​I'm not sure this scenario makes a difference in that I haven't seen the fan come on in my case. As I have said before my fan only comes on with the A/C is on. It would be interesting to see if anyone else can get their ICE hot enough to get the fan to turn on. :detective:

 

Another situation is in winter, when the cabin heating is on. In winter, even if the high speed battery is full, the engine is still required to run from time to time just to heat the water, to get warm air inside the car. When the water is warm enough the engine stops. But the water inside the heater core will cool down almost immediately, so the engine will have to be started again, even though the rest of the water in the circuit is still warm enough. Wouldn't it make sense to use just the water pump to bring fresh warm water into the heater core, without starting the engine? I like this idea. :)

 

Paul

Edited May 14, 2017 by ptjones

[Waldo]

 

Another situation is in winter, when the cabin heating is on. In winter, even if the high speed battery is full, the engine is still required to run from time to time just to heat the water, to get warm air inside the car. When the water is warm enough the engine stops. But the water inside the heater core will cool down almost immediately, so the engine will have to be started again, even though the rest of the water in the circuit is still warm enough. Wouldn't it make sense to use just the water pump to bring fresh warm water into the heater core, without starting the engine?

 

The Energi has a separate coolant pump to circulate coolant through the heater core. The Hybrid doesn't, presumably using the big pump would draw too much power to make it worthwhile.

[Vlad Soare]

Speaking of the Energi, how does it heat the cabin? Does it need to start the ICE every couple of minutes, like the regular hybrid does, or does it use electric heaters? Or maybe a combination of both (so that it still has to start the ICE, but less often)?

One way not to depend on the ICE would be to route the high voltage inverter's coolant through the heater core. But I'm not sure whether that gets hot enough in normal use.

[murphy]

The Energi has a 5 kW resistance heater to provide cabin heat. If the ICE isn't running it is blocked from the coolant loop so the resistance heater is not trying to heat the ICE. Use of the cabin heater reduces the range of the car in EV mode. If the ambient temperature is above 70 degrees F I get at least 25 miles out of the battery. In the dead of winter I get about 10 miles out of the battery. Cold doesn't hurt the battery but its efficiency is significantly reduced.

[Sychie]

mistake, please remove

Edited April 3, 2020 by Sychie