ianmacdon

Have had this buzzing noise from under the hood for about 5 months, getting progressively worse, hope someone can help with identifying the source.
This is a video taken from under the hood of my 2012 Mercedes 350 4M with about 100,000 miles on it, or 195,000 kn. I have had this intermittent buzzing noise coming from from the front of the car for about 5 or 6 months. It is getting progressively worse. Back when I first heard it, the noise would go away at the end of my street, now it goes about 3 or 4 miles until it finally goes away. We even raised the car on 4 jacks and disabled the ABS systems, let it sit all night, and spun all wheels but still not able to determine the source or the cause. There are no error codes aside from irrelevant ones unrelated to the abs , traction control or anything that would even explain this. I am hoping this video finds its way to anyone who has had this experience and have found the source. It is driving us crazy. The nearest service department is 250 miles away, and I am worried something will happen on the way . Hoping someone out there can help send ideas. Thanks

You Tube

BlackML550

​​​​​Did you sort it?

If you can't get to a mechanic I'd be looking at the belt drive and all the pulleys, the supplementary (electronic) water pump and even the air pump that links to the air filter housing. Scewdriver as a stethoscope the way to go.

ianmacdon

yes we found it , the drivers side bearing on the transaxle finally got really loud , then started leaking oil and then it got oddly quiet. I stopped driving it immediately and found the the axle shaft loose where it goes into the transaxle. Parts on order will update in a few weeks when we change it.