baileybonds

i own a 2005 cayenne s and have been noticing a significant humming sound coming from the front drivers side panel every time i turn the heater up in the climate control (anything past 74 degrees approximately). it gets louder the colder it is outside and is fairly consistent and annoying. i took the car into the dealer this morning to get this looked at/fixed, and i was told that the "heater noise" issue was not only common but a "standard characteristic" of the cayenne. he said that the noise is actually a water pump of some kind that works hard during the heat/ac process and that the sound was worse on the 03 and 04 cayennes, but that the 05 has a line of padding that is supposed to dampen the sound annoyance. i was shocked when he told me this, as i find the noise to be unacceptable, and now i don't know what to do.

has anyone else experienced this problem? and if so, any suggestions?

thanks,
dave
los angeles

Sloth

I know I ran the AC in my new 05 Cayenne over 74F this past weekend. It was in the high 50's in N. FL this past weekend and I did not notice any odd sounds at all...

BobbyB

I would check with another dealer - I've had my heater set at 76 the last few days when the outside temps have ranged from 12 to 28 and I've not heard any strange sounds at all. In fact the noise level of the heater/fan in my 04 is not any louder than the level in my previous Lexus.

pingwrx

I too have the buzzing/humming noise from the heater in my 2004 S. It’s very noticeable when the temperature setting is up (higher than 75 degrees) and the fan speed is low, (one click above off position) We have taken the car back to the dealer, and they acknowledged the noise, but said its normal (some kind of a pump), which I thought was strange for a $65K+ car. Anyway, we’ve kind of gotten used to it, but when the lease is up and I’m looking to trade for a new Cayenne, I’ll make sure the new Cayenne won’t have this issue.

Sammamish

I too have the same issue. I have been told similar lines by my dealer.
I think I saw a post last year of heater being replaced for similar issue.
Someone care of give it a search?

RUthless

Same complaint from my wife today - 5 degrees outside & it only happens when its very cold she says...

dervin1968

Hi,
I have a 2005 Cayenne S with the same issue. With mine the noise also went away when the fan is switched completely off. I took it to my dealer and they determined it was the second electric water pump used to pump and control the flow of the hot coolant into the heat exchanger inside the vehicle. They told me not to worry about it... But it is annoying at idle.

Dennis C

There was a TSB for this that included adding additional insulation to mute the noise. I had this "repair" done to my Cayenne, but it didn't help much. You'll get used to it.

Dennis C

I actually found my old post from 2008 on this.

The TSB is #1945 in which the concerns are listed as: "Additional coolant pump noise can be heard in the passenger compartment. Foam rubber strips can be installed on the coolant line brackets (holders) to eliminate this pump noise."