b2v

Over the past week two weeks I have heard at least one or two snaps when just driving straight at about 20mph. Then the other night I had to drive through about a 15 foot long flooded, maybe at or just below the rocker panel / frame. I drove a mile or two under 40/mph after that and did not hear or feel a vibration. Then the other day, after about 1/2 mile and the car reaching 4th gear, I got a vibrating hum. I turned around to head home and check it out, flushed brake lines which was well overdue and checked brake cylinders to exclude brakes as the issue. It would still vibrate, hum once in 4th gear. I tried manual with the paddle shifter and then it began making the noise once in 3rd gear and after a couple stop and go's trying to figure when exactly it starts, it began almost but not exactly once in motion. I uploaded a video to YouTube with a view of the underside and with the sound while in gear. I haven't driven it much to fully test if there is any performance loss, but there does not seem to be from what I could tell. Also, I've recently started using sport mode I rarely ever used in the past and did notice some excessive winding of gears getting on the highway. If it was the tire rod (no slop in either wheel though) or inner CV axel I was going to order the part and attempt the repair, but was hoping that someone with more skill in auto repair to take a look and listen before I decide whether to attempt the repair or bring it into the shop and if a straightforward repair, let me know if any special tools or parts I might overlook are needed. Thanks.

2014 E350 W212 Buzzing Hum Vibration 169,000
0:00 Driver's Side CV Axel & Tire Rod Area
0:19 Transmission Underside Area
1:07 Audible Buzzing Hum With Moderate Vibration

Raj1471

At the 3 sec mark on your video it appears that the sway bar link bushing is compromised and leaking grease. This might be the cause of the sound you're experiencing. Imo I would definitely replace both links. Do a YT search for W212 MB sway bar link...plenty of videos walking you through the repair if you were to tackle it as a diy.