Your Engine 101
Timing System
Troubleshooting Timing Belts
A timing belt gets its name because it times, or synchronizes, the movement of your engine’s valves and pistons and helps the ignition fire on time. On some engines, it also drives the oil pump, water pump and balance shafts.What's a timing belt?
A timing belt is a flat rubber belt with teeth. The teeth maintain precise timing between internal engine components to ensure smooth and efficient operation.
Timing belts are used in two types of engines: interference and non-interference.
Timing belts are used in two types of engines: interference and non-interference.
What’s the difference between an interference and non-interference engine?
A non-interference engine has enough clearance between the pistons and valves to prevent damage to these parts — interference engines do not — and so when a timing belt breaks, pistons and valves will most likely be damaged.
Do all cars have timing belts?
No, some use a timing chain. Timing belts are lighter, quieter and more reliable than a chain — plus they’re easier to install and maintain. Your professional service technician can tell you whether your car has a timing belt and if it has an interference or non-interference engine.
What happens when a timing belt breaks?
Your car stops — instantly. And it may have sustained severe internal damage to the valves, heads, pistons or cylinders — and that means severe internal damage to your wallet.
How can I avoid a broken timing belt?
Always have your timing belt checked according to your vehicle’s recommended schedule. Most manufacturers suggest replacing the belt anywhere from 60,000 to 100,000 miles. Check your owner’s manual or ask your service technician about the specific interval for your car. Remember, a timing belt is a consumable product, which means its life can be used up by the recommended time. So, if your owners manual doesn’t have a suggestion, a good rule of thumb is around 60,000 miles.
What are some common causes of premature timing belt failure?
Common causes of premature belt failure include tooth shear, tensile failure, edge wear, and back cracks. If your technician recommends replacing your timing belt, ask for a look — you’ll probably see symptoms similar to the above. Age or severity of operation, such as high commute times, stop-and-go driving, etc. can also effect the overall life cycle of the belt and bearings in the timing belt system.
Are timing belts difficult to replace?
Replacing a timing belt is a highly specialized process and should only be performed by a certified technician. While some belts may look alike, they definitely are not interchangeable. It’s very important to get the correct belt size and type for your vehicle.
While you’re having the timing belt replaced, ask your automotive mechanic to inspect and replace other parts of this system as well, like tensioners, idlers and water pumps. (The belt's sole job is to transmit torque and if one of the other components is failing such as a timing belt pulley or belt tensioner, the belt will soon fail as well, even if it is new.)
While you’re having the timing belt replaced, ask your automotive mechanic to inspect and replace other parts of this system as well, like tensioners, idlers and water pumps. (The belt's sole job is to transmit torque and if one of the other components is failing such as a timing belt pulley or belt tensioner, the belt will soon fail as well, even if it is new.)
Remember Timing Replacement
- It’s much easier to replace a timing belt today than an engine tomorrow. A new timing belt is a small price to pay for peace of mind.
- Engine timing belts may fail sooner, or last longer than what’s recommended in your car maintenance schedule (depending upon a variety of circumstances, including driving and temperature conditions). Even if your engine timing belt isn’t showing signs of wear, it’s an ABSOLUTE MUST to replace it at the recommended mileage interval.
