Annoying electrical fan from behind dash
 

So just the other week i started getting an annoying fan noise from in behind dash when I start up my car (pf d2 4.2q sport). Randomly cuts out for a few seconds every so often, then chimes right back in again until engine switched off.
Any ideas where to start

Is it definitely a fan noise or a clicking noise for several seconds, stops for a while and then repeats? If the latter, it will be one of the actuators that direct the air from the HVAC system.

Or perhaps the aircon compressor? Does it stop if you turn the aircon off?

Definitely a fan and not just a clicking. When it stops it’s just for a few seconds, then starts again

Think I tried switching the air con off too, and made no difference, but will check again this morning

So two possibilities ruled out. Next suggestion is fan bearings. Checkout the following page, and if you have access to VCDS or other diagnostic tool, there is a check you can run:

http://www.audipages.com/Tech_Articl...anreplace.html

Could be the blower motor in the colder weather.

Does the noise the vary or go away if you manually adjust the fan speed ?

Thanks will hook up vcds and see what I get. Haven’t done much on d2 with it used it more on my d3

No just a constant with the random stops I mentioned. Changing blower speed etc has no effect on it

How about the dreaded auxiliary coolant pump motor starting to fail? :rolleyes:

That ^ or the cabin temperature sensor inlet fan, which lives in the centre console above the hvac controls.