Cooling fan is always on, even runs when engine is cold

Our 2011 Subaru Outback 3.6R, which we bought brand new back in Feb ’11 and only has 4k miles, seems to be having issues with the cooling fan. The cooling fan will come on when the engine is cold and it will stay on the entire time the engine is running. I’ve read that the cooling fan will run the whole time when either the A/C is on or the vent control is set to defrost, regardless of whether the engine is cold or hot. In my case, the cooling fan comes on when the engine is cold, even with the HVAC off and it will remain running at full speed when the engine is running, again with the HVAC off.

Every time I go to start the car after it has been sitting for an entire day and the engine is cold, when I turn the key to the “On” position, before the engine is even started, the cooling fan comes on. How is this possible when the engine isn’t even running and the engine is cold. Again, the HVAC is off. Once the car is started, the cooling fan will remain on until the car is shut off. The fan is running as such a high speed you can hear it over the noise of the idling engine. Once I turn the car off the fan shuts off.

Since we’ve owned the car there were two other issues First, the transmission pan gasket wasn’t properly installed and it was leaking transmission fluid. That issue was fixed and is good now. The second issue was that oil was leaking from the timing chain cover. It turns out that the timing chain cover gasket was also improperly installed. This too was fixed, and doesn’t seem to be a problem anymore.

Could the cooling fan be running irregularly due to broken sensors? Could it be a bad thermostat? Do you think something could have been broken or incorrectly reinstalled when the technician had to remove the timing chain cover to fix the timing chain cover gasket?

Any feedback is appreciated.

Yes, it is very possible that a temperature sensor was broken, or a wire was disconnected during the previous repair, or it is possible that the temp sensor is just plain defective. However, the cause of the problem is not your concern as it is a warranty issue, plain and simple. EVERYTHING on your car is covered by the Bumper-to-Bumper Warranty (Subaru calls it the “Basic” warranty) for 3 yrs/36k miles, and the engine and transmission are covered for 5 yrs/60k miles by the Powertrain Warranty.

Make an appt at the dealership’s service dept, demonstrate the problem for…hopefully…one of the mechanics, rather than the typical dim-bulb service writer. If necessary, ask to speak with the service manager. If these tactics are to no avail, contact Subaru Customer Service at the corporate level. Contact info can be found in your Owner’s Manual.

Probably a stuck temp sensor.
Typically on the bottom of the radiator.
Could also be a stuck relay, but I’m not a Subaru expert.
Unplug the connector to the temp sensor. If it keeps running it’s a relay. If it stops it’s the sensor.

Great, thanks so much for the feedback.

FYI, I took the car to the dealer for inspection and they indicated that the fan control unit was bad and was shorting out. They reset the existing control unit in the iterim, which seems to be working fine for now, and they have ordered a new unit which will be installed soon.

It doesn’t matter because it is under warrantee, but I think someone is CYA mode. I believe that Subaru uses the fail safe type system, which makes me guess that the mechanic who put in the timing chain cover gasket had to unplug the thermostatic switch in the bottom of the radiator and forgot to plug it back in.

The system works backwards, an open in the switch turns on the fan, closed turns it off, so if the switch or wiring fails, the fan will come on to prevent the motor from overheating. But the switch could have gotten damaged too, but I think the reset was just plugging it back in.