E500 Front end whirring noise
 

My E500 4matic wagon has developed a whirring noise in the front end of the car .This sound developed kind of recently . I thought it was the tires but now I am not so sure . The sound is non existant at slow speeds up to about 20 to 30 mph but takes over after that and becomes louder than the engine . The noise is vehicle speed related and not engine speed related . If I kick the transmission into neutral at speed the sound is unaffected .There is no grinding or klunking with the car with extreme turning like with maneuvering into a parking spot .So I am wondering could it be the tires , the differential bearings or something else ? I made a short video which demonstrates the issue . Thanks for any help and advice !

Did you get under there to see if one of the axle boots is torn? It's a fairly common problem and they'll fling all of the grease out.

In my case, my front differential failed and broke my passenger front axle. It sounds just like the front the diff, but that was just in my case. I'd definitely inspect the axle boots, make sure nothing is torn, then check the wheel bearings. Does it whir more when the weight is on one side or the other? Does it stop completely with a side to side weight transfer? That may be a wheel bearing. There's a lot going on up there, so its hard to tell.

Chris

Whoa. I listened again with headphones on. That is LOUD! Mine was a higher pitched whirring.

Chris

I would not have thought of checking the boots , I will do that .I should probably mention the car has 155k miles on it . And I will be replacing the tires in a few weeks as they are getting down on the tread. I also noticed that the front tires wear on the inside so I don't know if that could be contributing to the noise.

The front tire wear like that could be from the alignment or worn suspension parts. With that mileage I'd be looking to do a lot of routine maintenance on the suspension if it hasn't been done before.

Could be wheel bearings.

After reading a little bit and watching a couple of videos I did three things to check the front wheel bearings and one is Jack the car up and tip up and down the tires to see if they move in a upwards and downwards fashion and they did not there was no play I also rotated the tires in neutral and there was no grinding noise or noise of any sort and I also took the car out on the road at around 50 miles an hour and swerved left and swerve right and the sound did not change at all which leads me to believe that it's not a bearing problem at all.
I did find my automatic transmission fluid was low which makes me wonder if it's the automatic transmission but I don't think it's that .
Does anyone know if the transfer case on this vehicle is connected to the automatic transmission or the automatic transmission fluid?
I hope to drain and replace the front differential fluid here in the next couple of days to see if that makes any difference.

I did check the boots while I had the car jacked up and they appear to be in perfectly good shape.

A way you could decipher if it's a wheel bearing is drive at a speed where you can hear the noise and sway back and forth while driving. If the tone or pitch changes then you got a faulty wheel bearing. If you see no change i'd be looking into jacking the
vehicle up on jack stands, put it in dyno mode and drive car on jackstands.

t/case is separate from transmission. uses different oil too. How is the U-joint on your front propeller shaft?

I did try the swerving at high speeds with no change in Pitch. I have not jacked up the car on stands and tried driving it that way. Also thanks for the information on the transfer case I did not know that. Thank you .

Issue resolved
 

In the end it was the driver side front wheel bearing that was causing the problem in addition to replacing that I replaced the passenger side front wheel bearing put on new brake pads in the front topped off the differential fluid and repaired a torn CV axle boot while I was in there working.

Video update
 

Finally merge my videos and uploaded them to YouTube so there's a synopsis of my bad bearing exploits .
https://youtu.be/sBUnaFiw1jE