WHOOPing sound...rear left corner.

[oliverexplorer04]

Howdy guys,

I've got an 04 Explorer, going strong and love the car to bits, had it since 06.

it's not without issue though, for about two years now intermittently the car has been making a whooping noise (like a windscreen wiper against a dry window)
the whooping is in various tones, and is sometimes very funny to hear. it makes the noise at all sorts of times and configurations, when i'm low on gas or when i'm full, when the car is hot and when it's cold, living in the desert the car is always hot, but more so in slow moving traffic it'll start doing it's whooping thing! i can categorically say it is not the wiper lol.

has anyone had this issue and what the hell is it????!!!!!

car is not affected when this happens, no loss of power or anything but it's just damn annoying!

my own thoughts are that it may be something to do with the rear air conditioning, as that's always making sounds it's self.

any help would be greatly appreciated!

Ollie

 

[2Trux]

I have that same noise, it rarely happens so I haven't put any work into finding it. My thought is it is a blend door moving as temps change and is dragging on the housing.

 

[Number4]

Rear left with rear AC is where the blower motor, expansion valve etc is all located. How's the climate control in the rear?

 

[oliverexplorer04]

yeah the whooping sound is reminiscent of blowing air through a reed clasped in your hands, but it will make lot's of different pitched noises. like whale song lol

climate control works fine, there are occasionally grinding noises or what i can only describe as a valve being prevented from moving, if you can imagine that sound, but that also goes away after a while.

i feel it is AC related, but other than it being mildly annoying i don't think it's doing any damage, there are definitely no error codes showing up. i rarely use the rear ac climate control, unless I've got a full car.

 

[turborich]

It's in the rear HVAC. I have the same noise from time to time but since it doesn't effect the performance of the A/C I just don't let it bother me anymore. Before I knew what it was I was worried LOL. Search it on youtube, there's a video about it somewhere.

 

[icepickjazz]

Here are several articles on the whooping noise for your reading pleasure:

Intermittent Whoop
2006 Whooping Noise

 

[Sandy Keller]

Here’s more info from other posters. My 2017 Explorer is doing the same thing and it’s getting worse.

I have had this loud intermittent "whooping" noise coming from the back of my 2005 Ford Explorer. Everytime I took it into the dealer, they couldn't find the problem. If it's making this sound, you need to replace the HVAC Heater/ AC Module in the back. Go to www.fordparts.com and plug in your make, model to order. Unfortunately, the part is expensive ~ $250. It will be delivered to your Ford Dealer. You can have your Ford dealership fix it. They will charge ~ $800 including the module. If you are mechanically inclined, you can fix it yourself. Here's how:

The simple solution to this problem is to evac and refill freon. The Explorers with rear A/C hold a huge amount of freon 1.33kg. The noise is coming from the expansion valve, I believe due to a small lack of freon in the system. Almost a month has passed with out a reoccurance where as it was a daily event.

its the ac system. its the anti ice thing, i cant remember if a reprogram or a new expansion valve. fixes this issue, i think its a reprogram of the pcm, how it controls the ac compressor.

 

[turborich]

UPDATE! My whooping noise wasn't what I thought it was.

My A/C compressor locked up, so I ordered a new compressor, accumulator and orifice tube. Vacuumed the system, recharged and the occasional whooping noise is now totally gone! A/C is also quite a bit colder. I'm seeing 38 degrees from the center vent and our outdoor temperature in the shade is 110 degrees. Not to bad.