Aspen456

My 2010 GL350 just developed Humming noise at front end, sounds like coming from engine department, the noise is very strong at speed 60~70km/h and about 120km/h, it doesn't change which ever the gear level, even in neutral. I did balanced the wheels, then changed the tires.
The noise disappeared at the top position when hit a bump (when the load on the wheels are lower)
This noise looks only related with traveling speed, it doesn't change when shifting to different gear.
I just changed the front air strut (Arnott) before.
Any members know what wrong could be?

alx

It is usually tires. If you changed them I would suspect a wheel bearing. If bearings check out next is front diff.

Aspen456

But unfortunately, the noise keep on same, it sounds like coming from the center of the engine compartment, and making the gas paddle and steering wheel vibrating.

I also noticed the noise was reduced significantly when making left turn (even slightly left turing), but stronger when making right turn

Could the problem be on front diff?

Aspen456

Diagnosed it in Canadian tire, told me it's the problem on Front/right bearing, will fix it on Thu., I will update the result after fixing done.

Aspen456

Canadian Tire replaced the front/right bearing for my vehicle, but noting changed, they are trying on the front/left side now.

Aspen456

Noise gone after bearings on both sides replaced.

alx

Lol.. If noise is reduced when making left turn it is the left bearing usually... If you told them your observation and they replaced the right bearing- I would ask for my money back on the right bearing replacement. This is classic bearing 101 material

C230 Sport Coup

Diff bearings. Google Mercedes front differential bearings.

alx

Not on this platform they are not problematic. Besides, he fixed the issue. You padding up your posts count? Lol

C230 Sport Coup

DOH! Sorry didn't see he replaced both wheel bearings and it was fixed.
Thats rather an odd one though, both wheel bearings going out.
Padding my post count? Ha. #5680 still can't compare with Glyn or a few others.