Timing Belt

Timing belt functions:

The timing belt is an essential part of any naturally aspirated engine, since it synchronizes the timing of your combustion process. First, your engine's pistons travel up and down in the cylinder, then intake valves open at the right time to let in air fuel. After, they close at the right time to allow the fuel to burn, then the exhaust valve open at the right time to let out the exhaust. All of this happens a thousand times a minute, and it is your timing belt that makes sure that the valves are opening and closing at precisely the right time.

On some engine, the water pump is driven by the timing belt as opposed to the serpentine belt. If that is the case, it is a good idea to replace the water pump when you are replacing the timing belt and vice versa, since much of the same work as to be done for either. The same is true for the timing belt tensioner. It should be inspected and possibly replaced.

There are two types of engine timing configurations, interference, and non-interference. In an interference engine, the valve’s stroke and piston’s stroke occupy the same space inside the cylinder. The timing belt main purpose is to keep them from smashing into each other, since they are moving one at a time.

In a non-interference engine, the valves and pistons do not take up the same space. If the timing belt snaps, the valve or cylinder remains intact. The only necessary maintenance will be to install a new timing belt to your engine.

What are the signs indicating a faulty timing belt?

A broken timing belt will cause your vehicle to break down immediately. Indeed, if the timing belt is off, your engine won’t run, and that is the best case. The worst case is that a valve is opening at the wrong time and collide with the piston. The result is bent valves and maybe even more damage to the cylinder head. Your certified NAPA AUTOPRO technician can replace the timing belt according to extremely specific parameters and repair any engine damage.  

  • It is difficult to diagnose a worn timing belt. Here are some common signs of a faulty timing belt:
  • Engine does not start
  • Squealing sounds from the engine
  • Engine misfires or runs roughly
  • Ticking and/or clicking sounds from the engine
  • Oil leaking from in front of the motor
  • Illuminated check engine light

If you recognize any of those signs, you need to contact your NAPA AUTOPRO technician for a timing belt maintenance.

How often do you need to maintain your timing belt?

Timing belt ware out naturally over time. A worn or broken timing belt can cause very expensive engine damage. Your certified NAPA AUTOPRO technician will inspect the timing belt during routine maintenance to check for any defects. The timing belt should be replaced according to the manufacturer’s recommendations—usually every 100,000 km.

Replacing a timing belt is one of the most expensive routine maintenance items on your service schedule. But, not replacing your timing belt can lead to some of the most expensive repairs you are likely to ever have. That is why it is important to have a regular inspection on your vehicle.

Learn more about the steering system from our NAPA AUTOPRO experts in the video below: