Noisy fan sound on 2005 997 tiptronic

[AlexH997]

I have a 2005 997 Carrera S tiptronic.

During the winter period i drive the with ECO on and I've never heard a fan sound running in the background.

With the decent weather recently I've turned the A/C on but I've noticed a background fan that runs in the background especially when I reach traffic. When I start driving it appears to disappear.

Is this normal?

[sneakybear]

I've a 2005 C2 as well and have had some fan issues.

First up, which fan is it? If one of the front radiator fans fails/gets a stone in it so won't turn (that was my problem a while ago) then the other compensates and it's pretty noisy. This'll be obvious if you put your hand in the wheel arches and feel & hear only one side blowing - obviously an issue to attend to...

Otherwise it could be the fan into the engine compartment which is also noticeable but not an issue... it'll happen once the temp guage in the engine bay reaches a certain level (coincidentally that guage also controls at which defined speed the spoiler raises) hence at traffic lights etc mine often cuts in when it's sunny and you've been stop start for a bit. If it's blowing constantly there is another fault that can cause this but it sounds like it's just coming on a lot rather than never turning off.

I'm sure there will be other suggestions from here, the guys are amazingly knowledgeable if you describe the issues well.

Out of interest why do you turn off the condenser in winter? I ask as I understood that they like being used periodically and aside from this I know they cut out below about 3 degrees (or is it 4?) anyway as less water to extract from the air.

Just hoovered out all the detritus that accumulates in the rad pockets over winter from mine last weekend... those leaves and cig butt ends all rot nicely.

Cheers,
sb

[AlexH997]

I have no need for the A/C during winter as I find it too cold and if suffer from dry eyes.

I can do in future but never heard that it needs to be turned on periodically before.

[Pope]

As a function of the AC system the radiator/condensor fans run at slow speed all the time with the system on.

With AC off, the fans only run to regulate coolant temp (over approx 95 degrees C)

[burman]

What sneaky bear said,- also recently had stone jamming nearside rad fan on my GEN 2 c2s. Offside fan runs flat out to compensate, when both are free they are very quiet.

[Polome]

As above ...switching on AC starts both fans at slow speed. Running with AC on during colder periods helps keep the compressor seals and moving parts lubricated and flexible. Pick a day if possible every two or three weeks ( when ambient is above low cut out temperature) and drive with AC on. Intake fan ballast resistors failing are also a common fault , stopping fan from running...a quick feel for air flow at each intake when AC is on confirms fan operation . On a very hot day , and if car been parked up and is toasting inside switching AC on will start fans on high speed ....when cabin temp reduces to normal levels the fans drop to low speed. Hope this helps....

[charge]

I have a fan sound coming from my car.
It really bothered me at first, so damed noisy, and never seemed to go away.
I asked a good local mechanic to take a look at it, and all he said was 'they are all like that!'
I have sort of got used to it now, I think the noise has even grown on me, sort of rising, when the engine is rev'ed.
When you look in the engine bay, there is a big orange fan type thing in there with two belts going to it. Do you think this is the cause of the problem?

Cheers