A noisy fan belt can be pretty embarrassing when you drive down the road and it attracts a lot of unwanted attention. Unless it smokes though, a noisy fan belt usually isn't a sign of a big problem.
- Skill level:
Turn off the motor of the car. Check the slack on the noisy fan belt by pushing down on it. If the belt has more that an inch of slack you will need to tighten it or replace it.
Verify that the noise is the belt and not the bearings. To do this, place a small amount of brake fluid on the fan belt while you run the car. If the problem is the belt, it will quiet immediately. If it doesn't, then the problem is the bearings.
Rub an old bar of soap on the fan belt to quiet it. With the car turned off, rub the soap on the inside and outside of the whole belt. This will apply a waxy coating that will prevent the belt from squeaking.
Start the car and listen for squeaking. If the fan belt is still noisy, turn off the car and rub more soap on the fan belt until it becomes quiet.