Loud Rear Air Fan

[bogucki]

I just bought a 2008 Expedition El Limited and my wife and I love it. However, the rear air is pretty loud when it is turned on. I've read about the failed actuators and I don't think this is related. (I've encountered the failed actuators on my wifes Tahoe and this sound doesn't appear to be the same)

The sound is coming from the right rear fan and is activated only when the rear air is turned on. The noise is in-sync with the fan speed; on high it is most loud and turning it down reduces the noise. It basically just sounds like a noisy fan, but I don't think this noise is within regular operating acceptance; it's too loud.

Is the fan motor going out? Is this common? Or are the rear air fans in these vehicles just loud? I can imagine on a long trip that this would be extremely annoying and probably inhibit any napping.

 

[MoHawk]

Mine is fairly loud too. However, I kinda got used to it. Napping isn't a problem.

 

[bedrck46]

the sounds of a Tahoe may be different than the sounds of an Expedition

Best bet would be to pull the fan and check it to see if anything is stuck in the fan blades I would expect it to be somewhat louder at high speed more than at low speed but worth checking'

Plus its not a good idea for the driver to be napping on long trips unless he pulls over and turns the engine off.

 

[bogucki]

Well, I wouldn't mind the noise if it was just the sound of air being moved by a fan, but it doesn't sound like that. It sounds like the fan bearings are going out or something. I was thinking perhaps the previous owner rarely used the rear air and the motor sat for too long unused.

I plan on pulling the plastic off and inspecting the fan, but wanted to make sure this wasn't a common issue with an easy fix before digging into it. And I seriously doubt that a tahoe air actuator sounds much different than an expedition air actuator. They're probably made in the same plant.

 

[Live Expy 2008]

I have an interesting issue on my '08 Expeditionand it may be on yours too. I thought I had a fan going bad in the rear of my Expy. Everytime I had my air on there was a dull hum at the rear of the truck and the speed of the truck is what changed the noise. I complained to my dealer several times on oil changes. About a year ago when I left from my oil change and they said they checked it, no sooner than I hit the boulevard it started. I turned around and right back to the dealership. The service tech came out, had me turn the air on and hung his head in the truck while I was turning the fan on and off and at different speeds.....nothing. He said next time I come in for an oil change to take a test drive with him so he can hear it.

I found out that the problem is air escaping the seal at the rear windows. The seals or the position of the rear windows when closed are weak and allow air to escape when the truck has air blowing in the cabin. I When I hith the power button to let the third row windows crack just a little, no noise. You may want to try that first and see if that is your issue. It may save you a trip and a headache or two.

Good luck.

 

[MoHawk]

^^ Those seals suck and I loathe them

 

[bogucki]

Interesting Live Expy, but I don't think I have the same issue. I don't have any noise when the rear air is turned off, even on the highway. The noise is directly related to the rear air fan speed and sounds like it is coming from the fan.

Even with the liftgate up, meaning cabin pressure equilibrium, the fan makes the noise, so I don't think it is related to the windows at all.