The noise will only get louder and stay longer.
I took off my grill with a flathead screwdriver, from the side, carefull not to break either of the two clips.
I then moved the sensor wire around until the noise stops, and packed the square shaft with foam.
On occasion, it has reoccured ... I adjust the foam (it takes 2 seconds), and bingo, blessed silence.
The dealer in Orillia, Ontario wants $85 for a new sensor, then between .5 and 1.0 hours to route the sensor around the asperator fan, and even then, no guarantees.
I no longer put up with the noise ... it really makes the car sound like a P.O.S. when driving, and never really goes away ... after warm up, you'll still hear a ticking noise if you turn off your blower and stereo ... a little foam around the wire sensor, and you're good to go.