A Humm?
Thread Starter
Junior Member
Joined: Aug 2016
Posts: 57
Likes: 4
2013 Mercedes C250 Coupe
A Humm?
So my car has 83000 miles, and drives well. Tires have much meat left. The last few days, at about 70 MPH, I hear a high pitch humm start and continues until I exit the highway, which would equate to slowing down I am thinking. It starts very suddenly as soon as I hit about 70, and to me sounds like an electric motor of some sort. It reminds me of the electric motor I hear in the coolant reservoir when I shut the car off sometimes. Does not sound like a tire at all....maybe a wheel bearing?, but I don't think so.....I am leaning toward some sort of electric motor. Anybody come across this?
Much thanks!!
Rob
Much thanks!!
Rob
MBWorld Fanatic!
Joined: Aug 2023
Posts: 3,878
Likes: 1,200
From: MA Coast
W204 2010 C300 4matic Sport M272
Hardest part is pin pointing where its coming from. I drive with the radio off most of the time and im hearing all sorts of noises, especially on the highway through Boston in the left lane and theres those moveable concrete fast lane barriers 1 foot from the car, seems the noise bounces off and drives me nuts. I once thought my horn was stuck on. Other times I thought my belt and pullies where bad so replaced them, still hear the noise sometimes.
have you tried putting the windows down to see if its louder when in happens on a certain side?
To check wheel bearings you should be able to jack up the car and spin the wheel, listen for a noise or feel for any vibration. I thought a sign of bad wheel bearings where usually when turning there's a grinding noise. It really could just be the tires. When one of my rear brakes was making a noise i had someone drive the car while I stood on the side of the street to listen for where its coming from, was able to tell it was the rear drivers side.
have you tried putting the windows down to see if its louder when in happens on a certain side?
To check wheel bearings you should be able to jack up the car and spin the wheel, listen for a noise or feel for any vibration. I thought a sign of bad wheel bearings where usually when turning there's a grinding noise. It really could just be the tires. When one of my rear brakes was making a noise i had someone drive the car while I stood on the side of the street to listen for where its coming from, was able to tell it was the rear drivers side.
Thread Starter
Junior Member
Joined: Aug 2016
Posts: 57
Likes: 4
2013 Mercedes C250 Coupe
I appreciate the reply. I am starting to think it may BE a tire, which I would rather, than something wrong with my car. Yesterday after work, I didn't seem to hear/feel it. I will have to see how and if it progresses.
Thanks!
Thanks!
