1998 Mercury Mystique Loud Humming Noise

JESSYH200503

MEMBER
1998 MERCURY MYSTIQUE
109,000 MILES

When I drive my car, I makes a loud humming noise just as soon I start. The noise stops of I turn the wheel slightly left ( or make a left hand turn) but will go back to the sound when driving straight. The sound is also there when turning the wheel right. The front tires are almost bald and I have year old winter tires on the back. My dad thought it could be the tires or even the transaxel. Thoughts?

1 Reply

CARADIODOC

MECHANIC
33,727 POSTS

Suspect the left front wheel bearing. Ford is the only manufacturer that still uses a pressed-in front bearing. The part is relatively inexpensive but they take a long time to replace, and special tools are needed.

The clue to this is your dandy observation that turning left makes the noise go away. That's because turning slightly to the left removes a little weight from the left bearing, and it gets quiet. You mechanic will double-check this by running the car in gear on a hoist and listening next to both bearings with a stethoscope.

This observation doesn't work on cars with bolt-on wheel bearings. The noise might sound like it's coming from the left, and it might even get quiet when turning left, but it can still be the right bearing that's noisy. The noise can travel from one side to the other. The bad one is identified with the stethoscope, but with this design, if you replace the wrong bearing you just put the old one on the other side. With the pressed-in bearing, those are destroyed to remove them so if you change the wrong one you have to buy another new one.