Why does my car overheat when the ac is on during winter -26 deg celsius?

[uchiepulini]

Why does my car overheat when the ac is on during winter -26 deg celsius? Should the ac be off during low temperatures like -20 to -35 deg celsius? When i try to drive, reading on my temperature gauge is one line above operating temperature.

 

[dishdude]

I can tell you the AC isn't running at those temps no matter what you have selected in the climate control settings.

 

[JellyBeanDriver]

where is 'one line above operating temperature'? Is it overheating or you just see the temp gauge a hair higher than normal?

 

[uchiepulini]

I can tell you the AC isn't running at those temps no matter what you have selected in the climate control settings.

Is there a possibility of engine overheat wit

where is 'one line above operating temperature'? Is it overheating or you just see the temp gauge a hair higher than normal?

Its noticeable above operating temp. Its only happening when my ac is on in -20c deg celsius weather or below. Or am i doing it wrong? Should the ac be off at those temperatures?

 

[Lubener]

Unless the coolant has boiled over, you technically did not over heat. If the gauge shows the temp just elevated, I wouldn't be concerned. Myself, I would connect a scanner showing live data and see exactly what temperature the computer is seeing.

 

[FowVay]

I don't know if this applies to all vehicles but technical data on my Nissan states that it will not activate the A/C compressor at temperatures below 35ºF. The explanation is that this design is to avoid any chance of moisture in the system freezing and causing damage to the compressor.

I seriously doubt your A/C compressor is engaging at -15ºF (-26ºC). Check your cooling fans for operation and the area around the condenser for ice formation or other possible air flow restrictions.

 

[RobbS]

Your AC compressor is running during defrost mode. Make sure your fans are running and the coils are clean.

 

[shortyb]

Your AC compressor is running during defrost mode. Make sure your fans are running and the coils are clean.

This. I've also seen condensors that freeze up in really cold weather and restrict airflow to the radiator.

 

[kschachn]

This. I've also seen condensors that freeze up in really cold weather and restrict airflow to the radiator.

Freezing up due to what I wonder? If it is really cold weather then it's not possible for the condenser to be colder than ambient, if the system was operating properly it should be warmer.

 

[shortyb]

Freezing up due to what I wonder? If it is really cold weather then it's not possible for the condenser to be colder than ambient, if the system was operating properly it should be warmer.

Moisture on the condensor fins that froze because the refrigerant was low and would not be warmer as you suggest.

 

[Capt W]

When i try to drive, reading on my temperature gauge is one line above operating temperature.

If you consult your owner's manual, you'll probably find your operating temperature falls within a range on the temp gauge rather than a single point. Here's an example from one of my Caravans:

The temperature gauge shows engine coolant temperature.
Any reading within the normal range indicates that
the engine cooling system is operating satisfactorily.
The gauge pointer will likely indicate a higher temperature
when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.

 

[kschachn]

Moisture on the condensor fins that froze because the refrigerant was low and would not be warmer as you suggest.

On the condenser? That's interesting.

Are you sure it wasn't convection evaporation that was causing the freezing?

 

[shortyb]

On the condenser? That's interesting.

Are you sure it wasn't convection evaporation that was causing the freezing?

Nope, outside, on the condenser. I thought it strange too, however, wasn't quite the -35F the OP was talking about. Usually, like you said, a properly operating system will keep the condenser warm enough to prevent ice formation.

 

[zzyzzx]

Have you considered not running your air conditioning in -26 degrees C weather?
I normally wait for it to get much warmer than that before using air conditioning.

 

[Gyro Gearloose]

OK, fasten your seat belt for a somewhat convoluted explanation of a similar experience I had several years ago. I had a 2008 Impala that was taking longer to warm up in the morning and would run hotter on cool days than on hot days. This engine had an interesting cooling system with the thermostat on the lower radiator hose rather than the upper, and the thermostat was designed with rubber ring under the plug to ensure tight shutoff of coolant from the radiator. It also had an extended plunger that formed a valve inside the engine block to simultaneously restrict the hot coolant recirculation to the water pump as it opened up the cold flow. Somehow the rubber ring came loose one day and got wedged under the thermostat plug so that a trickle of cold coolant was always seeping through from the radiator. The end result was that on cold days the thermostat flowed enough coolant to keep the engine cool but did not open enough to block the recirculation from the block and the engine would run hotter on cool days than on warm days.

The problem also had a somewhat interesting resolution. On really cold days (teens F) the engine computer would detect the extended engine warmup time, display a message that the engine was OVERHEATING, drive the temperature gauge to full hot, and turn the fans on high speed. I guess that was GM's back door approach to getting you to change the thermostat, which is the first thing I would try in this instance.

 

[930.engineering]

Why does my car overheat when the ac is on during winter -26 deg celsius? When i try to drive, reading on my temperature gauge is one line above operating temperature.

Very most probably your car doesn't "overheat" and your gauge appear to have a range for an acceptable operating temperature, not one single point. See your owners manual.
.

 

[stormgol]

we lack a ton of information. what year and model vehicle ? maintenance history, mileage. it's complicated giving an answer when you have close to no details.

 

[Jetronic]

Nope, outside, on the condenser. I thought it strange too, however, wasn't quite the -35F the OP was talking about. Usually, like you said, a properly operating system will keep the condenser warm enough to prevent ice formation.

yet some systems use frost sensors

 

[TimeFlies]

At -26 I generally turn on the heater, not AC, call me crazy.

 

[97prizm]

Why does my car overheat when the ac is on during winter -26 deg celsius? Should the ac be off during low temperatures like -20 to -35 deg celsius? When i try to drive, reading on my temperature gauge is one line above operating temperature.

It could be the water pump is worn, or an air pocket in the system. What type of vehicle and what year? Is it possible that the gauge or sensor is going bad? Second you should run the A/C briefly in the winter to keep the pag oil circulated but I don't think you're supposed to run the A/C in that Cold temperature.