Noisy fan belts aren't necessarily an indicator that anything is wrong with your car, but they can be annoying for you, your passengers and other people on the road. Squeaky fan belts are an easy issue to remedy--all you need is five minutes and a bar of inexpensive soap or some inexpensive dish soap.
Prepare to fix the squeaky fan belt by ensuring the car is off, the parking break is on and the bonnet is open.
Locate the fan belt. The fan belt is associated with the radiator, which sits at the front of the engine compartment. The fan belt will be attached to the fan mounted on the radiator.
Rub the moist bar of soap along the inside and outside of the whole fan belt, thoroughly covering the belt. If using dish soap, deposit a quarter-sized drop of soap on one hand, rub your hands together, and then coat the belt with your soapy hands, applying more dish soap as necessary.
Clean your hands with the rag.
Turn on the car to see if the belt still squeaks. If so, apply more soap.
If the fan belt shows significant wear--such as cracking--or is lax, then it needs to be replaced by a professional mechanic.
If the belt won't stop squeaking, take the car to your mechanic. It's possible something is wrong with your car and it's not your fan belt, specifically.