My brother is in the Army and is stationed in Watertown, Ny. It gets pretty cold there and he says the heat in the car stops working when it reaches -8 degrees. Anyone have any idea what the problem could be?

Thanks in advance.

 

There are not enough details in your post. How long does the car run before he has heat? Does the heat work at all other times? Does he have a short commute to work or make any short trips? More details would help you get better responses.

 

Sorry bout that. He drives the car around the town, but he lives on base, so there's no commute to "work."

He does drive home every weekend which is about a 5-6 hour drive.

He told me that the heat wouldn't work even after the car is fully warmed up. But works when it's like 10 degrees out. Just not when it reaches ~ -8

 

Has he checked his antifreeze concentration? It might not offer enough freeze protection at very low temperatures.

 

Worth checking the anti-freeze as it's easy to do and a simple fix. Although, it seems a little unlikely it's the anti-freeze. If the thermostat was frozen up, and the heat wasn't working that would mean there was no water flowing from radiator to engine to heater block. So, that would account for no heat, however if he is taking a 5-6 hour drive the engine would surely over heat (probably in like 15 minutes even at -8 degrees outside, assuming no flow between radiator and engine due to frozen thermostat). I had this happen on an old Toyota pickup of mine. After letting it sit for 20 minutes or so with an almost over heated engine, the engine heat eventually thawed the thermostat and voila. Would expect that to happen in this case as well if it was truly a frozen thermostat.

I'm assuming that 'the heat doesn't work' means that the fan DOES work, and just blows cold air. If that's the case and the engine isn't overheating, I'm at a bit of a loss. Must mean that no hot water is hitting the heater block but it seems odd that that would be temperature dependent. If it was an antifreeze problem where it was freezing in the heater block, you would expect it to thaw eventually (in a matter of minutes after the rest of the system had warmed up) and work.

If the fan isn't working then maybe there's a problem with that electrical connection that is temperature sensitive.

Sorry for the long post.

 

I have that happened to me like 2 times. I drove for like 30 mins, but still no heat. I just turn off my car then started my car back up then the heat comes on again.

 

Thanks, I'll tell him to check his levels.