: Engine block heater? Will it help efficiency.
03-01-2013, 06:06 PM
I have been thinking about the Volt in cold climates, I live in Utah. Would a block heater help keep the car warm, and be better for gas mileage? Since on cold mornings the engine coolant would already be warm, I think it would make the engine run more efficiently since it would be warm and get better mileage? Just wondering if anyone had tried it. Block heaters are cheap at around $30.
03-01-2013, 06:22 PM
Preconditioning does just that, warms the coolant.
03-01-2013, 06:35 PM
Ditto Dave !!!!
03-01-2013, 07:25 PM
If you precondition with the car still plugged in what would you really be $aving since the block heater would be sucking electric at the same time (presumably) you would be charging? Doesn't make cents to me..but what do I know anyway?
Preconditioning warms the coolant and it also turns on pumps to circulate the warmed coolant that through the battery. Therefore, I doubt that an engine block heater would do much for electric mode efficiency. However, if you have a 2013 and would use Hold mode at the start of a trip to force the ICE to generate heat then a block heater might help.
If I preheat the car, I then have to recharge my battery for a couple of hours, to get my full charge. So by using a block heater, it would warm the engine, BUT, since you have a full charge, the engine wouldn't start for a while, because you are using 100% electric, so the engine would get cold again and I'm getting confused :-)
03-01-2013, 07:54 PM
I'm not sure a block heater will help much, though it might. A recirculating coolant heater like the Zerostart series would prevent/delay ERDTT (assuming it can get the coolant over 104F,) and let the engine move to closed loop a lot sooner.
The sad part is the car has all of these pieces built in already, better than any add-ons, but there's no 'engine warm' mode in the programming to open the cross link valve, and turn on the electric coolant pump and electric heat. With a couple software switches, the Volt could do all of this using thx existing wall plug and hardware. Hopefully it'll become an option in a later version or someone will figure out a hack. :)
If I preheat the car, I then have to recharge my battery for a couple of hours, to get my full charge. ...
Preconditioning runs for 10 minutes and can be done twice before starting the car. If the car is plugged into a Level 2 EVSE during preconditioning most of the energy will come from that connection and it should take only a few minutes to fully recharge the battery. I understand that if the car is plugged into a Level 1 EVSE, it could take some time to recharge. I have no first hand experience with how long that will take but there are threads on the forum in which members report their experience. Recharge time will differ based on current temperature, average temperature over the past day or so, etc. Try it. It might not take as long as you anticipate.
...BUT, since you have a full charge, the engine wouldn't start for a while, because you are using 100% electric, so the engine would get cold again and I'm getting confused :-)
If you have a 2013 you can force the engine to start immediately by using Hold Mode. Earlier model years do not offer that feature.
03-01-2013, 09:42 PM
I have to think the energy used with the overnight block heater would not be paid back by the drive dynamics. I'm at 39 to 40 mpg on the highway for my longer commutes now and that's on 32-35F mornings. I would hate to void a warranty by using one. Maybe if I were in Calgary, it could help when overnights are -20F.
03-01-2013, 11:34 PM
I'm not sure a block heater will help much, though it might. A recirculating coolant heater like the Zerostart series would prevent/delay ERDTT (assuming it can get the coolant over 104F,) and let the engine move to closed loop a lot sooner.Nice post. It seems like it could shorten the length of the ERDT[L]T. I've had mine kick on in just a minute after I've left the 'warm' garage.
As I recall when I was doing the ScanGuage and temp testing that I saw the water-temp/WT rise when I preconditioned but you didn't see the same thing.
See my maroon update in this first post that corresponds to all this! http://gm-volt.com/forum/showthread.php?11181-COMFORT-setting-limiting-quot-Engine-Running-due-to-low-temperature-quot-ERDTLT
03-01-2013, 11:48 PM
Preconditioning warms the coolant and it also turns on pumps to circulate the warmed coolant that through the battery.
Just to clarify, cuz the wording was kind of ambiguous...
The engine/cabin heater coolant is separate from the battery coolant. The battery coolant might also be warmed during a precondition by the battery heater and pumped around inside the battery pack. But since this thread was about an engine block heater, I didn't want people getting the wrong idea about it sharing heat or coolant with the engine.
03-11-2014, 11:00 PM
I would strongly recommend NOT using a block heater.
The vehicle computers use off time as a chance to check temperature sensors against one another. Once a vehicle is off for a period of time (example 5 hours) the Ambient Air, Intake Air, Coolant Sensor, and others should all be close to one another. Using A block heater may cause DTC's to set for temperature sensors, and could cause other drivability issues. If the vehicle is in full control of coolant temps, no problems.