Fan and airco e53 2004 3.0 D Auto

[Smeeagain]

At the end of a very long run (600) miles the other day, as I was switching off I could hear the fan kicking in. Fine I thought cooling it after long hot journey. Next day srarting from cold could hear the fan kicking in again, which if it has ever done that before Ive never noticed. Fan doesnt kick in now but aircon has lost its icy chillines and its just averagely cool at best (it was regassed) only 3 months ago
Are both things connected do you think or just coincidence?
Another 600 mikes back home today and will have aircon pressure checked tomorrow but interested to hear your thoughts
Smee

[Colin]

Hi Smee  it took me two attempts with different garages to get my aircon sorted , first guy talked the talk BUT he didn't seem confident  but finished the job and off i went  and all seemed good , like you 3 month later it lost the chillines , went to a more trusted recomended guy had full check of the system and regas , he said the first time it may have leaked because of dry seals ,  so far its still chilly and thats 6 months ago , i can't say iv'e heard my fan kick in ! , .. Colin ..

[Smeeagain]

That's great thanks, so are you saying there is a link between fan kicking in and the aircon?

[X5Sport]

The aux fan should start when the a/c is on, though at low speed unless the outside air temp is high.  No fan, or low pressure and the a/c compressor clutch may not engage.

[Smeeagain]

Ive got the opposite though - fan but no a/c ....???

[Smeeagain]

Bump. Still getting aux fan kicking in on short journeys and ac not cold enough - can these two things be related or entirely separate issues?

[Colin]

Smee you say AC not cold enough  so i take it the compressor is kicking in  and if it is  then if i were you i'd get it pressure checked  and regassed if necessary

[Smeeagain]

Yes I'll be doing that, but my question is, is there/could there be a correlation between the aux fan kicking in and the ac bot being cold?

[Smeeagain]

Ok I'll ask the question in a different way. Forget the a/c - why has the aux fan started coming on on short journeys (and ling journeys too)?
Smee

[Colin]

I don't know  but maybe the fan always has done this , when you start the engine you say you can hear the fan start or kick in is the AC button on or off ??

[Smeeagain]

The fan hasnt always done this. I usually only hear it if the engine is getting warm in stationary traffic then it kicks in. Happens both with/without the ac button on

[Colin]

Is there only one fan up front to do all the cooling  or has the AC got its own separate fan

[X5Sport]

Should be two.  Engine driven on a viscous coupling and an electric one if I remember my E53.

[Smeeagain]

[quote="X5Sport"]
Should be two.  Engine driven on a viscous coupling and an electric one if I remember my E53.
[/quote]

Yes youre right there separate. Trying to conclude if AC not working wpuld create a situation where aux fan has to kick in? Does ac cool the engine in any way or only the cockpit?

[henrym3]

AC fan (nearest front) is primarily to cool the condenser and should run if AC is on. It should kick in if the engine temperature gets to high and beyond the capability of the viscous fan. Although that would have to be a very hot day in traffic queues or a faulty viscous fan. (in my experience) I think the temperature sensor is in the coolant pump/thermostat housing