Warning Signs of an Aging Timing Belt

While you may not pay much attention to your car's timing belt, it plays a vital role in the mechanics of your vehicle. The timing belt is an engine component that rotates the engine's cam and crankshaft in sync, ensuring every cylinder fires at the appropriate time. You can find your car's timing belt under a timing cover near the front of the engine, and since it was likely manufactured from performance-quality rubber, it will need to be replaced every now and then. In this post, we will look at a few common symptoms that may indicate your timing belt needs repair.

Like any piece of equipment, a timing belt will deteriorate with time. It is best to check the owner's manual or ask a trusted professional to know if your engine has a timing belt or chain. A broken timing belt will cause your engine to fail completely and potentially cause damage to other parts of the engine. It is essential to replace the belt while it is showing warning signs to avoid it breaking unexpectedly. 

Time is perhaps more important than miles. Seven years is the maximum life of the timing belt recommended by most manufacturers. For example, the belt should be replaced even if the engine has only 30,000 miles but is seven years of age. More timing belts break due to age than mileage.

If your timing belt is beginning to deteriorate, you may experience any one of the following warning signs:

• A ticking noise coming from the engine

• An oil leak near the motor

• Your engine runs roughly

• Your vehicle's engine won't turn over

• Overall poor vehicle performance

• You experience frequent exhaust issues

• You have problems with your RPMs

• Poor fuel efficiency

Do you think your vehicle might need a timing belt replacement? If so, we invite you to bring your vehicle to Neighborhood Tire Pros today!

Your car's timing belt is responsible for maintaining the precision that's crucial to your engine's functions. Essentially, it coordinates the rotations of the camshaft and crankshaft so the engine's valves and pistons move in sync. The expected lifespan of your timing belt is specific to your car and engine configuration, usually between 60,000 and 100,000 miles. (You can check your owner's manual or look online for your car's service schedule.)

The manufacturer's recommended intervals are a safe guideline; you probably won't need to replace your belt any earlier [source: Allen]. However, if you're approaching your service interval and have doubts about the belt's condition, you might as well get it replaced a little early. It'll be less expensive than waiting until after the belt breaks.

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Why is it important to replace the timing belt on such a strict schedule? The belt is a synthetic rubber strap that contains fiber strands for strength. It has teeth to prevent slipping, which fit into the grooves on the end of the camshaft and crankshaft. It's a simple part for such an important function, and when it snaps, things get a lot more complicated. Unlike many car parts that gradually lose function as they wear out, a timing belt simply fails. Whether the belt breaks or a couple of teeth strip, the end result is the same. One minute, your car will be running perfectly; the next minute, it won't. You're in trouble if your car has an "interference engine," in which the valves are in the path of the pistons. If the camshaft or crankshaft moves independently in an interference engine, there will be at least one valve/piston collision. The fragile valves will bend, and you'll be faced with a costly repair.

It's easy to check the belt for signs of premature wear -- just locate it in the engine bay (usually under a plastic or metal shield that should be easy to remove) and check it for drying, fraying and discoloration.

The belt itself is inexpensive, probably costing less than $20 at an auto parts store. Your mechanic will probably charge several hundred dollars (or more) for a belt replacement service, though. Those hours spent dismantling and reassembling the engine bay add up quickly.

You can replace the timing belt yourself if you have access to the necessary equipment. In some cars, it's a straightforward procedure -- remove the engine covers and shrouds, line up the camshaft and crankshaft, slip off the old belt, and slip on the new one. Sometimes, though, it's a lot more complicated. For example, the timing belt might loop through a motor mount, in which case the mount would need to be removed to access the belt. You'd need an engine hoist or stand to safely remove and replace the mount [source: Juran].

Keep in mind that an error in this job, such as improperly turning the engine by hand or failing to coordinate the shafts, will cause the same damage as a snapped belt. Make sure you understand the procedure before getting started.

Need more help with the do-it-yourself approach? The next section will point you in the right direction.

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I did a timing belt on the friend of my brother’s Toyota a few years back. The car had the original belt, was probably 14 years old at the time, with about 140K on the clock

But as soon as I took off the cover, it was clear the belt wasn’t long for this world. The rubber was getting pretty soft, and was severely cracked.

On my own personal vehicles, I always changed them by mileage or time, whichever came first.

My old service writer’s philosophy was to change timing belts when they break . . . but he didn’t know nearly as much about cars as he thought he did. That’s why he wasn’t the one turning wrenches.