When an engine is completely ruined, most drivers would assume the owner of the car has ignored major warning signs, or perhaps the car was just extremely old. However, this isn't always the case. Sometimes, letting just one part fall by the wayside can result in a total engine loss. That's why it's especially important for drivers to pay close attention to their timing belt.
What does the timing belt do?
Engines have lots of moving parts, and two of the more important ones are the camshafts and the pistons. The way engines are designed, these critical parts need to be on an exact schedule. The camshaft's job is to open and close the valves, which in turn let gas and air into the engine. The pistons are connected to the crankshaft, which ultimately makes the wheels turn. However, if these two parts are not synchronized, the pistons and the valves could collide and cause major damage.
That's where the timing belt comes in. The belt is essentially a piece of rubber with ridges on it that runs between two gears. The belt is connected to the camshaft, so the entire system is regulated as the belt moves in a loop. Just like the inner workings of a clock ensure the hands move at the correct pace, the belt keeps the camshaft moving in a predictable timeframe so it doesn't collide with the other parts of the engine.
Interference vs. Non-interference engines
This is incredibly important on "interference" engines. This is a type of engine where the pistons and valves are extremely close together. Thus, a failure of the timing belt means the engine will likely suffer major damage. The pistons and valves will collide, and it's possible that parts may be lodged within the valves, preventing fuel and air from getting to the engine. You'll likely notice this when you hear a loud banging noise followed by your car slowing to a halt.
"Non-interference" engines are designed with a bit more space between the pistons and valves. This doesn't mean you can simply go driving around with a broken timing belt - you can still do a lot of damage to a non-interference engine if it breaks. For the most part, however, the engine won't be a total loss if you address the problem quickly.
Keeping tabs on your timing belt
Keeping this in mind, it's quite easy to avoid any kind of damage at all - as long as you're proactive about your timing belt replacement. This is one of the aspects of vehicle maintenance that you should pay close attention to as your car gets up there in age. If you've bought a used car, it's probably best to assume the timing belt hasn't been replaced and take the precautionary measure of getting a new one.
Otherwise, use your owner's manual to locate the timing belt. Typically, it will be underneath a cover designed to protect it from heat and chemicals. With the engine off, examine the belt and note any cracks or frays - this could be an indication the belt is likely to snap. Another problem is the vehicle's fluid coming into contact with the belt, so check for any residue from oil or coolant.
Monitoring your timing belt is very important for proper vehicle maintenance, so those who don't want to end up with total engine failure should be sure to check their belt on a regular basis. In addition, it's beneficial for car owners to learn if they have an interference or non-interference engine - either by asking a mechanic or looking it up online - so they know how concerned they should be about this part.