I am having the same issue with my 07 Endeavor SE AWD..When I start to decelerate from 50mph on down, I get that loud whistling noise..I brought it to the dealer because they had to do a recall, so i figured i would have them check that out too..The shop manager told me the Rear hub bearing is bad..I asked him if thats why the truck is making that whistling noise and he said yes...They should get the part in the morning and fix it and i will have the truck back tomorrow night..Hopefully it gets fixed but I will keep you guys posted

 

Well, here I sit Feb 21st 2011. Last week, they told me to bring the Endeavour back and they would give me my money back.. Go Figure..?

They have changed the Transmission, the Valve Body, and now (last week) the Transfer Case.. Same noise same speed, same thing. :-(

I was told last week to go vehicle shopping and be prepared to bring my vehicle back..
I'm sorry I can't help any one here.. but, maybe they will take yours back? Of the Six months I've owned the vehicle, almost 10 - 12 weeks of it, has been in the shop..
This "headache" is coming to a close? I hope?
IF things don't go well, I'll keep you posted.. because until the money is in my hand.... I wont feel this is over!

 

Just to keep everyone informed.. I have a new 2011 endeavor in the garage.. I was asked to test it out, and if I was happy, they would exchange the new one for my 2010. My 2010 still whistles at 81 kms, and it has over 12,000 kms on it.
The new 2011 is quiet, but I wonder.. do I take the new Endeavor and be happy, or do I ask for my money back, and run? I'm not feeling to confident reading other stories here..

 

Personally I'd take the new car. Overall Endeavors have been highly rated. The chances of owning two problem vechicles aren't high.

 

Well, here I sit patiently waiting for the Dealer to swap out the goodies I bought extra for mine.. I should have the new on by the end of this week.
Good Luck every one..
I'm praying I don't hear a whistle... ever again...

 

My 2004 Endeavor is doing the exact same thing, nearly sounds like a turbo slowing down whistle but there is no turbo on it, I am thinking vacuum hose or air intake or something it first started after a very long drive (400 miles) and the car had around 100K. It doesn't sound like a friction thing like a bearing it doesn't do it at idle or when revved in neutral and it is intermittent. Somebody mentioned the center console I am going to try the cabin air filter and the engine intake air filter, it's an air noise but not from body or trim.
Despite this and it is annoying I wouldn't change my endeavor for anything!!!

 

Well my on again, off again whistling is now mostly on and it's also louder. I just took it to the dealership and they said that the driveshaft needs replaced....about 1000 dollars. Said it is the "driveshaft bearings". Does anyone know if the entire driveshaft needs replaced to change bearings? Not sure what I am going to do. I'm scared to death to drop 1000 on it and not have it fix the noise.

 

Yes, the bearing can be replaced. Not completely necessary to change the entire drive shaft.

 

My 2004 AWD whistled after about 35k mi. They replaced the rear drive shaft (warranty) and it stopped.

 

My whistling sound came back.

6 months later, its doing it again. Took it back to the dealer, they actually had the Mitsu district rep take a look at it, he agreed to replace the entire rear differential. The lead tech said that was what kept causing the pinion bearings to go bad, since that part has been replaced once already. Getting the differential replaced next week, hopefully this is the end of it.