Humming noise on rolling gear

MarkyBoy

Senior Member
Joined
Sep 8, 2009
Messages
84
Reaction score
0
Hi all, C250TD 1998 model.

It has developed a humming noise at speeds above about 30mph which gets louder the faster you go. It's something on the rolling gear as it makes the same noise when coasting. It does not sound like a wheel bearing rumble but more like very loud tyre noise (it's not tyre noise, they are fairly new) or bad road surface kind of constant hum.

Any ideas what could be casuing it, it sounds like it's coming from front of car but hard to tell exactly as the noise fills the whole car!
 

davidsw

Senior Member
Joined
May 24, 2011
Messages
386
Reaction score
0
Location
cornwall
Your Mercedes
Jaguar XKR ,Jaguar S-Type, Porsche Boxster S
Engine under tray ? Wheel arch liner ?
 
OP
M

MarkyBoy

Senior Member
Joined
Sep 8, 2009
Messages
84
Reaction score
0
  • Thread Starter
  • Thread starter
  • #3
Thanks, I checked the wheel arch liner and engine under tray, that's all fine
 

brandwooddixon

Senior Member
Joined
Jul 31, 2006
Messages
3,465
Reaction score
237
Location
Wolverhampton
Your Mercedes
CL500 Bluefficency 2012
**n.y.m. you've already mentioned tyres***

I was going to say worn tyres, but you've said that they're relatively new.

Have you jacked up the car to see if there is any bearing play or felt vibration?
 
Last edited:
OP
M

MarkyBoy

Senior Member
Joined
Sep 8, 2009
Messages
84
Reaction score
0
  • Thread Starter
  • Thread starter
  • #6
Prop bearing, could be a possibility as it has had a slight whining noise for about a year now. The whining stops when free wheeling but the humming is constant. Does that sound likely?
 

Corned

Senior Member
Joined
Jun 25, 2012
Messages
1,470
Reaction score
5
Age
119
Location
East Midlands
Your Mercedes
2005 S211 E320CDI Avantgarde
Either a bearing somewhere, or are the tyres directional ones with an arrow-head pattern?
 

CRH71

Senior Member
Joined
Jun 11, 2012
Messages
90
Reaction score
0
Location
Kent
Your Mercedes
C250 TD
What you describe is exactly how my issue started out. I'd get the rear wheel bearings checked if I were you - it turned out that my NSR one was shot to pieces, yet the noise (when it finally got worse) was definitely worse when the OSR was loaded.

However, when the noise started, it was a constant rubbing noise, varying with speed and present whether under load or coasting. It lasted 6-7 months like that before getting much worse - quite suddenly.

When was the axle oil last changed? Might be worth doing it again in case it's just old oil causing the noise.
 
Top Bottom