What is a timing belt?
A timing belt is a rubber belt with teeth, that is designed to keep the upper parts of the engine (Cylinder head and Camshafts) turning at the correct speed, in relation to the lower part of the engine (crankshaft and pistons).
Why does the vehicle manufacturer specify replacement of a timing belt at certain intervals?
Timing Belts are rubber, and constantly in motion when the engine is running. They experience wear and tear from friction with the timing gears, and the rubber breaks down, stretches, and loses strength as it gets older. To ensure the continuing integrity of the belt, manufacturers specify when to replace it with a new belt. This helps the vehicle owner to not experience a timing belt breakage or failure. Each engine design and belt are engineered differently, and as a result, there is a wide range of specified intervals. For most vehicles, the interval is between 50,000-105,000 Miles. Most manufacturers recommend replacing a timing belt every 7 years, regardless of mileage.
What happens if the timing belt breaks or fails?
In all cases, when the timing belt breaks or fails, the engine will not start or run, and the vehicle will have to be towed for repairs to be made. In most cases, major internal engine damage occurs, because the pistons will make contact with the valves. The cost to repair major internal engine damage is usually thousands of dollars, sometimes requiring complete engine replacement. Some engines (called non-interference or free-wheeling) will not suffer any internal damage when the belt or fails.
Why is it recommended to replace the water pump when servicing the timing belt?
On most modern engines that utilize a timing belt, the water pump is located behind the timing belt and covers, and often is physically driven by the timing belt. The typical life expectancy of a modern water pump is around 100,000 miles. In most cases, because of the extensive amount of labor that is involved with replacing the timing belt, the added expense of replacing the water pump at the same time offers the vehicle owner a substantial cost savings, when compared to replacing the belt at the recommended interval, and then replacing the pump soon after, when it is likely to fail.
Can you check the condition of my timing belt to see if it needs replaced?
It is very difficult to determine the age and subsequent wear of a timing belt, especially when the belt is still installed. On many vehicles, just getting the covers off to inspect the belt would be a costly operation. If there is any question whether the belt has been done within the service interval, or if there is any question as to the quality of the parts used or the installer's competence, we recommend to replace the belt.