5 Things to Know Before Buying Automotive Timing Belts

5. What Does a Timing Belt Do?

In short, the timing belt synchronizes the movement of the crankshaft and the camshaft or camshafts. We realize that this short answer may be a bit oblique, so we'll go into a bit more detail!

SBT are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

When you're driving, combustion is continually taking place inside the combustion chambers, or cylinders, of your engine. For this combustion to happen, precise timing is necessary. In each cylinder, an intake valve will open to allow a mixture of fuel and air into the chamber. The intake valve closes, and a piston is pushed upwards into the cylinder to compress the fuel. A spark is lit, which causes the mixture to combust. This combustion pushes the piston back down, and an exhaust valve opens up in the cylinder to let the gases out.

Your engine will have one or more camshafts, which control the intake and exhaust valves. In addition, the pistons are attached to a crankshaft. This shaft converts the linear energy (caused by the piston moving up and down) into rotational energy. The timing belt makes sure that these shafts are synchronized so that the valves and pistons are always in the right place at the right time.

4. What Happens When a Timing Belt Breaks?

It depends. If you have an older, non-interference engine (also known as a freewheeling engine), a broken timing belt will cause the engine to stop working until the belt is replaced. However, most modern engines are interference engines, which changes things greatly.

Interference engines are more powerful and efficient than freewheeling engines because they allow the pistons to create even more compression. They do this by making it so that a fully-extended piston occupies the same space in the cylinder that an open valve would occupy. This makes timing exceptionally important. If the timing belt breaks and the rotation of the camshafts and crankshaft aren't synchronized, the pistons may fully extend while the valves are open, striking them and causing massive engine damage. In cases like this, it's usually cheaper and better to replace the engine entirely rather than attempting repair.

3. Do All Vehicles Have Timing Belts?

No. Your car assuredly does have something to control the timing, but it's not always a belt. There are three main ways to control timing, though one isn't used as much as the others. The least-used method is actually the earliest: a timing gear. These gears are sturdy and won't snap, but they're also heavy and loud, making them less suitable for passenger cars. So, timing chains were invented. These work similarly to timing belts, and they're lighter than gears. Timing belts are actually a more recent way of controlling timing. They began to replace timing chains because they're even lighter and quieter. However, many modern vehicles have begun to be outfitted with chains again, since a timing chain should last for the life of the vehicle.

To find out whether your vehicle has a timing belt, check your owner's manual.

2. Why Do Timing Belt Replacements Cost So Much?

If your Chevy does have a timing belt, you'll find that replacing it is one of the most expensive automotive services. This is not because the part itself is expensive; as a simple rubber belt, it's actually relatively inexpensive. The difficulty comes in the labor. The timing belt is buried deep in the engine, so changing one means dismantling the engine. This alone takes hours of work, but it's not all they do. Generally, technicians will also replace the water pump, tensioner, and idler pulleys while they're replacing the timing belt. They'll also test the belt to make sure that the timing is correct before reassembling the engine.

Want more information on Automotive Timing Belts? Feel free to contact us.

1. How Will I Know if My Timing Belt Needs To Be Replaced?

The only reliable way to know this is to have it changed according to the service schedule in your owner's manual. This is because timing belts don't give reliable signals that they're going to break soon. That's not to say that there are no symptoms; for example, a timing belt that's worn down may make a ticking noise before it breaks. However, going by symptoms is a bad idea. A ticking noise can also be caused by a number of other things, so you may not know that it's the belt about to break. Also, timing belts don't always make this noise; sometimes they just snap with no warning. To avoid massive engine damage, make sure you follow the maintenance schedule in your owner's manual exactly.

5. What a Timing Belt Does

To get a better idea of what a timing belt does, it's good to take a quick look at the combustion process of a gas engine. Intake valves in the cylinders of an engine open up to allow a mixture of fuel and air into the combustion chamber. The valve closes, and the piston moves up the cylinder to compress the mixture of fuel and air. A spark plug ignites the mixture, and the combustion pushes the piston back down again. An exhaust valve opens up, allowing the waste gases to be pushed from the cylinder as the piston returns to the top of its stroke.

The pistons are attached to a crankshaft, which turns the piston's movements into a rotational output. Camshafts are what open and close the intake and exhaust valves. The timing belt is there to make sure that the movement of the camshaft or camshafts is synchronized with the movement of the crankshaft.

4. Why a Broken Timing Belt Is So Bad

Older vehicles used free-running or non-interference engines. In these engines, the pistons and the valves never occupy the same space in the cylinder. However, most modern engines are interference engines. These engines allow the pistons to create even more compression, producing more powerful and more efficient engines. The trade-off is that the valves and the pistons would occupy the same space in the cylinders if the valves were open and the pistons fully extended.

The synchronization of the crankshaft and camshafts means that this shouldn't happen--but a broken timing belt means that these two parts will no longer be synchronized. In a free-running engine, this would lead to reduced engine power and eventual stopping of the engine entirely. But things are different in interference engines. The pistons are likely to move up and strike the valves while they're still open, and that results in serious damage to a variety of internal engine parts. This is incredibly expensive to repair, and can sometimes cause enough damage that it might make sense to get a new engine--or a new car--rather than repair the damaged one.

3. The Symptoms of a Failing Timing Belt

Sadly, there usually aren't any symptoms that a timing belt is going to fail. There may occasionally be some small signs, like a ticking noise that might come from the engine. However, these symptoms are easy to miss, and hard to properly diagnose (since they can be caused by other problems, as well). Often, a timing belt will simply break with no warning. It's for this reason that it's vital to get your timing belt replaced when your owner's manual recommends. Doing otherwise is taking an awful risk.

2. Why Timing Belt Replacement Is Expensive

The timing belt itself is a simple rubber belt, and you'll find that the component itself isn't all that expensive. But call any place and ask for an estimate on replacing a timing belt and it will be hundreds of dollars. Why is this? Changing the timing belt on a vehicle is a long and labor-intensive process. To replace the timing belt, technicians have to dismantle a significant part of the engine, which takes time. They'll check seals, pulleys, tensioners, and more, before removing the old belt. Afterwards, they'll need to set the proper timing and test it to make sure the belt is working as it should. Finally, they will reassemble the engine. This takes hours of labor, and requires exceptional skill. Because of this, timing belt replacements tend to be some of the more expensive services your car will need. However, it's still cheaper than rebuilding an engine.

1. Not All Vehicles Have Timing Belts

If your owner's manual doesn't let you know when you need to have your timing belt changed, your Toyota may not have a timing belt at all. Instead, it might be equipped with a timing chain. As the name indicates, a timing chain serves the same purpose as a timing belt, but is a metal chain instead of a rubber belt. Unlike timing belts, timing chains likely won't need to be replaced. However, they're also heavier and louder than belts.

For more information, please visit Audi Timing Belt Replacement.