News

If you’ve ever heard a squealing sound under your hood, chances are it was your serpentine belt. Your serpentine belt is a long belt that’s driven by your engine. It winds around several accessories that power important automotive systems in your sedan. Let’s go over them.

First, the serpentine belt drives your air conditioning system. It spins the compressor that makes the cool air that takes the edge off the summer heat in St. Louis.

Next, the belt powers the alternator. The alternator creates electricity that’s used by your sedan’s electrical systems and also charges your car battery. Without the alternator, the battery will go dead in a few miles.

The serpentine belt may also run the pumps for both the power steering (some are electric) and power brakes (some use vacuum boost).

And, on most sedans, the serpentine belt powers the water pump. The water pump circulates coolant through the engine to keep it within normal operating temperatures. On some St. Louis cars, the water pump is powered by the timing belt instead of the serpentine belt.

When they understand what it does, St. Louis drivers realize that if it breaks, it affects a lot of systems. That’s why manufacturers have recommended that it be changed every so often so that it doesn’t fail.

At Master Auto Repair, we can perform a visual inspection of the belt to see if it has any cracks that signal the belt could fail soon. If the belt has more than three or four cracks every inch, has deep cracks that penetrate half the depth of the belt, is frayed, is missing pieces or has a shiny glazed look, it needs to be replaced regardless of age or mileage.

If it has lost a significant thickness, it also needs to be replaced. There’s a special spring-loaded pulley attached to the engine called the tensioner pulley. Its job is to make sure there’s a constant tension on the serpentine belt so that it doesn’t slip. The spring can become worn and no longer provide the necessary pressure to keep the belt tight. At Master Auto Repair, we recommend that the tensioner be replaced at the same time as the serpentine belt.

As mentioned, a squealing sound could be a sign that the serpentine belt needs to be replaced. It may be loose if you hear a slow, slapping sound when idling your sedan.

All in all, the serpentine belt is an important part for the function of your sedan. And it’s not that expensive to replace at Master Auto Repair – so it’s good to do so before it fails.