Engine Cooling Fan Behavior

[abbotlex]

Cold weather has finally come. I have noticed that my '05 Vibe does not warm up very fast. After starting it the other day, then getting out for something I realized the fan was running full speed. Does the fan always run even when cold? That doesn't sound right and would explain the long warm up times.I now also question it's behavior last summer. I never heard the fan run after turning the car off. I've had a number of cars that run the fan for a few minutes after turning off when the engine is hot.Do I have a problem? If so, where is the likely point of failure?

[Raven]

The fan runs no matter what the temperature is when you have the heater in the defrost position. The A/C kicks in to remove moisture from the air and reduce frosting. The fan always runs when the A/C compressor runs. The fan does not run when the car is turned off unlike some other vehicles.

[abbotlex]

Ah-ha! I totally forgot about the defrost/AC factor. Thanks for pointing that out.

[Simply Me]

In really cold weather (-20C) shouldn't the engine fan only kick in when the engine temperature needs to be reduced? So, when trying to defrost the windshield, the heat generated by the engine would be used for cabin heat/defrost..... My engine fan is on all the time too, and not helping to warm the cabin one bit !!

[djb383]

With regard to the defog/defrost vent positions, page 3-32 of our '05 owners manual it states "the a/c compressor will run atomatically in this setting........UNLESS the outside temperature is at or below 32F/0C." So, if the a/c and fan are engaged when temp is below freezing, something is wrong. The quickest way to get the engine to heat up (better heater performance) is to drive it......not let it sit idling. Put your heat control in the floor position, not defog/defrost, until the engine starts to heat up.

[abbotlex]

The AC compressor and fan are obviously different components. I believe there is a circuit that will prevent the compressor from running when it is too cold or if there is not enough coolant, or pressure, in the system (the electromagnet clutch won't engage), but the fan will run simply because defrost or AC is "on."

[ned23]

Quote, originally posted by abbotlex »Cold weather has finally come. I have noticed that my '05 Vibe does not warm up very fast. After starting it the other day, then getting out for something I realized the fan was running full speed. Does the fan always run even when cold? That doesn't sound right and would explain the long warm up times.I now also question it's behavior last summer. I never heard the fan run after turning the car off. I've had a number of cars that run the fan for a few minutes after turning off when the engine is hot.Do I have a problem? If so, where is the likely point of failure?When you say the car is "Not warming up" do you mean the engine temperature or the cabin temperature? Different answer could mean different issues.

[abbotlex]

Quote, originally posted by ned23 »When you say the car is "Not warming up" do you mean the engine temperature or the cabin temperature? Different answer could mean different issues. Engine temperature (well -technically- the coolant) warm up is slow. The cabin temp (heater) warms as soon as the temp gauge starts moving up.If I have the defrost off, the fan does not run and the engine warms a little bit faster.