The engine is used to propel the car forward, and it is also responsible for providing power to every other system in your car, from the air conditioner to the cooling system. The power is transferred from the engine to these different components by the serpentine belt. This part is made of rubber and does not last forever, so it is important to inspect it for signs of wear or damage every now and then.
Serpentine belts are typically expected to last for five years or 50,000 miles, but added stress and extreme weather conditions can shorten the life of the part. A good rule of thumb is to inspect the belt whenever you perform regular maintenance, such as an oil change. You should examine the belt thoroughly to ensure you don't miss a sign that could leave you stranded. If the belt snaps or is too loose to work properly, you will lose power to crucial parts of your car, which may lead to overheating and other issues.
When you visually inspect the belt, check for signs of wear, such as cracks, tears or holes in the material. You also need to take the belt's alignment on each pulley into consideration. The rubber material should rest straight on the pulley. You can test this by turning each pulley. The rubber should stay in contact with the straightedge the entire time. While you're looking at the pulleys, check them for rust and other signs of damage, as a broken pulley could lead to a broken belt. Replace these parts as needed.
Another thing you need to check is the tautness of the serpentine belt. Does it hang loosely around the pulleys or it is difficult to move? There should be a small amount of give in the belt, and most vehicles have automatic tensioners that keep this in check. If you notice the belt is sagging or too tight, the tensioner may be malfunctioning and will need to be replaced. It could also simply be that the belt is wearing out, but it's always a good idea to check the tensioner, just in case.
When choosing a new serpentine belt, you need to keep a few things in mind. The belt should have the same groove pattern and width as the one it is replacing. It should also be a tiny bit shorter than the original. If the current belt has been stretched out or you're just not sure how long the belt should be, you can consult the owner's manual to determine the appropriate length for the new part.
Whether you are simply inspecting the serpentine belt or you're going to replace it, it is very important that the car is off, cool and the ground (black) wire of the car battery is disconnected. When a car has recently been driven, there is a chance that messing with the belt can trigger the electric fan, which may put you at risk of injury. The belt can typically only be put on in one way, so if you're having difficulty you should stop and make sure you're approaching it the right way. Putting the belt on the wrong way will turn the pulleys in the wrong direction, which can damage the different pulleys and parts.
Once the belt is in place, you can use a manual adjuster or let the automatic tensioner do its job to tighten the belt in place. Some newer vehicles do not have tensioners. In this case, the belt will need to be stretched over the final pulley. Get the belt partially over the pulley and then manually rotate the to help ease the belt into place.