The internal combustion engine of a car is composed of a number of cylinders – usually 4, 6 or 8. Each cylinder contains a valve, which allows the gas and air mixture that the car burns as fuel into the cylinder where it is then combusted. For the car to run properly, the valves must function according to a predetermined sequence and set of intervals. The timing of these intervals is controlled by a timing belt, timing chain, or timing gears which control the opening and closing of the valves.
The terms timing belt, timing chain or even timing gears, are specific to each make and model of car. Different manufacturers use different methods to accomplish this timing function and call the resulting equipment by different names. What is common to all cars is that this function has to happen by some method.
Timing systems have nothing to do with cars specifically, but to any internal combustion engine – whether it belong to a car, boat or airplane. It’s interesting to note that timing chains were used in World War I to make sure machine guns could fire between a propeller and not cut it in half. This was an important technological innovation at the time, which meant that one person could both fly the plane and fire its guns at the same time.
When a mechanic says that a car’s “timing is off,” it means that the values aren’t firing in the proper sequence or at the proper intervals. This can be caused by either a fault or failure in the timing system, with the result being that the car that can’t run properly.
To find out what kind of timing system your car has, you can either take a look under the hood or ask your mechanic. The systems are usually easy to see and access – they’re subject to constant wear, so providing easy access for repairs is important. Whether your car uses a belt or a chain is readily evident upon visual inspection. Timing gears may be encased and hard to see – for this, you may need a mechanic’s help.
A car will let you know immediately if it has a timing problem, and the severity of the problem is usually directly related to how poorly the car runs. Belts usually allow the car to continue to run as they begin to fail, but noises will come from the front end of the car as the belts begin to crack or fray. Depending on the make and model of the vehicle, this may be a repair you can do with minimal training and tools. Timing chains, on the other hand, don’t fail as slowly as timing belts. When a timing chain begins to fail, the car usually becomes difficult, if not impossible, to drive fairly quickly.
Finally, timing gears don’t fail incrementally at all – they fail all at once and the car stops. They are also the most difficult timing system to repair, almost always requiring a mechanic. However, the advantage they do provide is that they’re more durable and fail less frequently. Again, the specific type of timing system you have will be determined by your vehicle’s make and model. If you feel strongly about the timing system your car has, you’ll need to do your investigation before purchasing the car in the first place.
