Another “What is this noise and how do I fix it” thread…
 

2010 E350 4 MATIC. 165k miles on it. I don’t drive it often but lately there’s been a grinding/rubbing/humming sound coming from the front of the car. It’s not all the time and there’s nothing specific I can do to get it to make noise. When I drive in the grass or turn it usually starts making this noise but doesn’t go away until i come to a stop. If I start moving again, it doesn’t come right back. Also, I’ve got this noise going forward, backwards, as well as in neutral and rolling down the driveway. I just replaced the brakes because I thought it was a dragging caliper. Wheel bearings don’t seem to have any play when I move the tires back and forth. Any input would greatly be appreciated.

https://m.youtube.com/shorts/DiIZHLy-z8k

https://m.youtube.com/shorts/woZKOoOaaa0

At first, I thought it was the power steering pump. Now, not so sure. Have you checked the PS fluid?

Not the PS pump
 

It’s not the power steering pump… I checked all that out and it’s fine. I lubed up the caliper slide pins and the lower pin on both sides seems really stiff and gummed up. I thought that was the issue but after doing that it’s still giving me fits. I’m going to tear apart the front brake system again and clean and lube everything and report back to see if it’s a brake issue or something else.

I have no idea, but could it be your front differential? My car is RWD, so I don't know if you need to service your diff or not.

I’ve heard that they definitely need attention and my mileage is getting up there. I’ll check it out! Thanks

Where is the neighbors cat...and, do you live in an area with large snakes? (I have seen both instances).