Hi - New to the Forum. I have a '98 V70R AWD with 85K miles. The auxiliary air fan comes on as it should when the car is cold and goes off. It's noisy enough that I can hear it running. Many times when I stop at a light or when I pull into my garage, it comes on again, does its 2 minute cycle, and shuts off again. Any ideas what the cause might be? It does this both with my factory ECU and with my IPD Power Pack ECU, so I assume it's something else. Thanks, Neal

 

Any codes in the system?
A bad coolant temp sensor will make it come on.

 

Tech - no codes, unless I unplug the pump, then I get the appropriate code (forgot the number) on my OBDII reader. Where is the coolant temp sensor? Easy and relatively cheap to install I hope?

 

The coolant temp. sensor is located in the thermostat housing.
I would do the thermostat and sensor.
It is easier to get to the sensor when you have the upper part of the housing off.

 

Tech -The car developed a slow leak in one of the heater hoses last week so I had the thermostat and sensor replaced while the system was drained to replace the hoses. The air pump still comes on intermitently, like when I stop at a light or pull into the garage - at least those are the times I hear itcome on. Any other thoughts? The car has 86K miles. Thanks

 

Did you check the relay for water?

Also make sure no one installed a Vaccum pump for the brakes.

 

I think I have the same issue. The best way to describe the noise is that it sounds like a circular saw. In fact the first time I heard it I thought somebody was inside the garage cutting wood so I did not open the garage door.

The noise seems to be coming from under the driver side headlight. Right next to the radiator/coolant drain valve. This part looks like a smallwedding cake, it could have a fan inside, haven't looked to deep. Anyway the unit seems to have disconnected from the rubber mounts that support it.

ARE WE TALKING ABOUT THE SAME PART?