Mazda Belt Tensioner Buyer's Guide
Without a belt tensioner, the serpentine belt can’t power various parts within the engine. The belt tensioner is an important part. As an owner of a Mazda vehicle, you need to know a thing or two about belt tensioners. This buyer’s guide has you covered!
What Is A Belt Tensioner And Why Is It Important?
If you look at the serpentine belt path, you’ll find the belt tensioner. It’s a small component that keeps the serpentine belt tight enough to spin all the pulleys on its path. This post explains what a belt tensioner is in more detail.
The belt tensioner is an important part in your engine. It’s because the serpentine belt needs it to power various parts. The belt tensioner also keeps the belt correctly seated in the other pulleys.
How To Diagnose A Failing Belt Tensioner
Belt tensioners last longer than serpentine belts. Yet, they’ll fail sooner or later. When that happens, the tensioner can no longer keep the belt tight enough. This causes various parts to lose power. That leads to a variety of performance issues.
This guide walks you through the process of diagnosing a failing belt tensioner. You don’t need any specialized experience or tools to inspect the belt tensioner. You only need to:
- Spin the tensioner pulley to see if it’s spinning smoothly
- Tug on the serpentine belt to see how the tensioner pulley reacts
- Visually inspect the tensioner for clear signs of damage
How to Replace a Mazda Belt Tensioner

Do you have a bad belt tensioner? Do you have a 12 mm wrench? If your answer to both questions is yes, you can replace it right at home. It’s a pretty easy job. We put together a tutorial for you. Here’s a general overview of the process:
- Remove the serpentine belt
- Remove the old belt tensioner
- Install the new belt tensioner
- Put the serpentine belt back on
- Check the serpentine belt to see if it’s tight enough
Check the tutorial for more detailed steps.
OEM Vs Aftermarket Mazda Belt Tensioners
Before buying a replacement belt tensioner , you need to decide between getting an OEM or aftermarket unit. This comparison guide explains why OEM is always the better choice. To sum it up:
- OEM belt tensioners always have the correct dimensions
- Mazda uses high quality materials to build its belt tensioners
- Mazda offers a good parts and accessories warranty
If you read the post, it’ll become quite clear to you that OEM is the better option.