buzzing noise airco fan (?)

[mudman2]

I replaced the AIRCON fan yesterday ($165) I thought it was going to be straight forward and it was except for 1 PIA screw (as usual) but it fixed the noise (a lot of crickets singing) now I can be warm again.

Thanks guys

Sorry for the quality of the pix, camera phone I'm afraid, being to lazy to break out the good one.

Mike

Hi RFM,

Thanks again for the quick reply.

Regarding the after coolant pump (TSB 1945). This has been done (correctly I hope) and the sound is still there.

I thought of the warm water pump as well. But could this make noice as well when the engine is running?

Thanks, frank

[CT44]

Finally found this post - I am having the exact same issue...I just need to do some of the test below to be 100%

Did you ever figure this one out? I am going to attempt to figure this out and can use any info you found so far...

JR

Hi,

Finally had the TSB1945 done at the workshop. Unfortunately the sound is still there. I did some more investigation:

- sound comes from the left (driver) side from the cayenne turbo.

- sound is best heard under the engine lid, left towards the dashboard (where the brake fluid (?) is)

- sound only appears when the engine is warm

- airco on off does not make a difference

- when the fan is off the sound is gone

- fan on and the sound is there

- when the temperature is set low the the sound is gone

- when the temp is set to warm the sound is back.

Sound is best described as a continuous humming sound. What is turned on permenantly (linked to the fan) and could make this noice (not the fan!!)??

Any ideas, I am slightly puzzled on this one.

(Air suction?)

[mudman2]

Just turn the fan down to the setting before OFF and it will disappear if its the fan.

My deal said they have replaced many

Finally found this post - I am having the exact same issue...I just need to do some of the test below to be 100%

Did you ever figure this one out? I am going to attempt to figure this out and can use any info you found so far...

JR

Hi,

Finally had the TSB1945 done at the workshop. Unfortunately the sound is still there. I did some more investigation:

- sound comes from the left (driver) side from the cayenne turbo.

- sound is best heard under the engine lid, left towards the dashboard (where the brake fluid (?) is)

- sound only appears when the engine is warm

- airco on off does not make a difference

- when the fan is off the sound is gone

- fan on and the sound is there

- when the temperature is set low the the sound is gone

- when the temp is set to warm the sound is back.

Sound is best described as a continuous humming sound. What is turned on permenantly (linked to the fan) and could make this noice (not the fan!!)??

Any ideas, I am slightly puzzled on this one.

(Air suction?)

[CT44]

Not the fan then - only stops when hitting off and starts at the first click on...

Edited April 22, 2008 by CT44

[jeffwest5599]

Anyone have the TSB they can share for this or what to do.  I cannot find it any where not can I figure out how to get it from this site.  Cannot become a Contributing member or see what that entails.

 

Jeff

[Orient Express]

Many times a buzzing from the HVAC fan is because of either some leaves have fallen into the cowl air intake on the passenger side of the vehicle in the front engine or trunk area, or more likely on older cars like 996/997/986/987s is that the foam inside the HVAC blower box has started to deteriorate and a piece of foam is now rubbing on the fan.  You can easily access this area where the fan is, by removing to cow plastic covering the cabin filter, removing the cabin filter and cleaning out all of the stuff that has collected in the fan area. 

[lewisweller]

The buzzing noise is likely the auxiliary water pump item 16, (not sure your model year or options though).

It's mounted behind the left driver side Wheel arc cover. 

Fan on is the signal for the pump to run if calling for heat. It may be coolant temp dependant as well but not sure hence won't make noise if engine cold?