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2012 Comfort setting, NO HEAT

3912 Views 29 Replies 11 Participants Last post by  emartin00
Well, it's been almost 6 years, and I've never had an issue with getting heat when I want it. I'm used to barely getting warm air in ECO, but today I had it in COMFORT and HI, and still the heat wouldn't come on.
So I did a remote start a couple minutes before leaving, but not long enough to really warm it up. When I got in, the air was slightly warm. Just after leaving my driveway, the thermometer dropped to 22F, so ERDTT kicked in. It heated up quick and provided nice warm air for about 5 minutes after the engine stopped. I kept it in COMFORT 76F for a while, and the air started getting cooler. I turned the temp up to no avail. I'm fighting a bit of an illness, so the cold was bothering me and I was getting frustrated. The engine never kicked back on either (and no HOLD).

Finally I stopped at a stoplight and shut the car down and restarted. When it came back on, the temp read 28F and the heat kicked on instantly. I had warm air in under a minute.

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Well, it seems have had no heat more often than not the last couple days. Guess I'll be making a trip to the dealer.
Can anyone point me to any more info on the software update? Also, since I well out of the B2B warranty, am I going to have to pay for this?
Well it turns out it may not be a software issue at all. I popped the hood when I got home, and lo and behold, the coolant reservoir near the firewall on the passenger side appears to be empty... I've never seen a pool under my car, but I haven't checked that particular reservoir in a while. TBH, I kind of forgot there was a third.
I'm assuming that's used for the heating system.

Anyway, I've got an appointment with the dealer for Monday. Guess I just need them to do a leak check and flush/fill.
I guess you missed the gurgling sound that typically accompanies low coolant.
I actually did notice that on Wednesday night. That's what prompted me to check the coolant.
I'm a bit at a loss as to where it went. The radiator looks fine, and I've never seen any puddles under the car.
Just for kicks and giggles, check your oil level.
It does appear to be a bit high, but it also doesn't look or smell contaminated at all.
It wouldn't hurt to send a sample out for analysis, I'm figuring the coolant had to go somewhere if you're not finding any puddles.
I'm going to throw a couple gallons in it this afternoon, and we'll see what happens.
I have an appointment Monday at the dealer too.
Yes, Dex-Cool, which you can get pretty much anywhere.
True, you CAN get Dex-cool nearly anywhere, but the correct mix uses deionized water in it's 50/50 premix. This is NOT generally found on your local autopart store shelf. Remember, the Volt uses a 360V electric heater and this special coolant uses water that is compatible with the high voltage heater since it's a shared coolant loop with the engine.
Not sure where you guys are from, but I had no trouble finding it...
The water in Prestone isn't "regular water" either. They are the same thing.

Update: Drove to work yesterday, and after adding coolant, the heat started working again. When I came out a couple hours later, there was a clear puddle near the front passenger side of the car. Really hoping it's not a hole in the radiator, but it seems like it might be coming form that area. Although the engine radiator is behind the battery radiator, so I'm not sure how it could get damaged.

It's at the dealer now. They didn't have time to get to it yesterday, so they gave me a free loaner Cruze (base model) and man is it boreing. Also, terrible tires, and we had 3" of snow this morning, so that was fun.
As long as the water has been deionized.
Per WOT:
WOT Says: “When topping up or replacing coolants, always use pre-mixed Dexcool® coolant and NEVER add regular green anti-freeze or tap water to ANY of the Volt’s cooling systems. This premix coolant (available at your GM dealer) is essentially a 50:50 mixture of GM Dexcool® (or other GM6277M compliant coolant) and filtered low-silicate, deionized water. The use of deionized water in hybrids, EREVs, and EVs is a necessity to ensure high-voltage isolation and to prevent the internal corrosion of cooling system components.”
Which if you look at Prestones details, it says nearly the exact same thing.
Turns out it was just a broken hose clamp that was causing the leak. That's one heck of a load off. $175 for the repair and full coolant flush and bleed.
Considering I was expecting a busted radiator, I'm feeling much better now.
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