Noise and vibration


#1

2000 Mercury Sable Wagon, 3.0L engine in very good condition. 72,000 miles. Just started making a loud growl/hum in the front end at 30mph. Gets louder the faster you go until 70mph where it gets a little quieter. When it starts to growl/hum, you can feel vibration in your feet. Steering wheel is steady, no vibration. Does anyone have any idea as to what this could be, or how to troubleshoot?


#2

The noise might be from a worn front wheel bearing. To check for this, raise the vehicle until a tire is off the ground. Grab the tire at the 6:00 and 12:00 oclock positions. Now try rocking the top and bottom of the tire in and out. If there’s play in the tire, that wheel bearing is worn. Or, grab a coil on the strut spring and slowly rotate the tire. Sometimes the roughness of the bearing gets transmitted into the strut spring where it can be felt.

Tester


#3

Thanks, I will lift the car and do the 6/12 o’clock test.


#4

I jacked up the car and there was no play in the tires. I spun the tires and there was no bearing noise coming from the wheel bearings. Has anyone ever experienced bad wheel bearings without the telltale play? The CV joints sounded normal when tire were spun, as compared to vehicle that is not experiencing the growl/hum. Can someone please help??? The wheel bearings on this vehicle are not replaceable, you have to change out the entire hub at $60 a pop, otherwise I would just replace them to see if this corrected the problem.


#5

Another check for bad wheel bearings is to turn the steering wheel off-center while driving (i.e. changing lanes). The pitch of the sound should change.

Ed B.


#6

Yes! You can perform these tests, and it still won’t reveal a faulty bearing. These are quick-tests.

The suggestion of listening if the amplitude of noise changes with steering direction is another quick test for a bad bearing.

Tester


#7

Had a friend bring me his car with the same problem after he had the front hubs replaced. The noise continued after the repair. It turned out to be his tires. He is now going back to the mechanic to sit on him for a while.


#8

Thanks for the replies. This is definetely not tire noise… The sound also does not change with a change in steering wheel direction.