Every vehicle has the number of routine maintenance jobs that need to happen in order to keep the vehicle running over the course of its life. In the short-term you're going to need to do things like changing your oil every 5,000 to 7,500 miles or so, you're going to need to keep the air pressure up in your tires, and you'll need to make sure you're keeping things like your wiper fluid and coolant topped up. Over a longer timeline you'll need to be keeping an eye on your brake fluid levels and transmission fluid. And along with that, you'll need to also be keeping an eye on your timing belt if your vehicle has one.
Not every car has a timing belt these days, many modern vehicles made in the last 5 to 10 years have switched from timing belts to timing chains. The timing chain does the same job as a timing belt, but it's made of metal and is more durable. You can expect these to last far longer and they technically don't require maintenance, but that's not always true because the unexpected will happen from time to time.
Some models of vehicles do continue to use timing belts however, and if you have a vehicle that's several years old it may also be using a timing belt as well. If this applies to your vehicle then you need to know how long your timing belt has been in use, and then you'll know how much time you have before you likely need to have it replaced.
What Does a Timing Belt Even Do?
As the name suggests, the timing belt is responsible for the timing of your engine. Your engine is a very precise piece of machinery and many things have to happen in the exact correct order for it to work properly. Your timing belt is looped around a pulley at the end of your crankshaft. The other end of the belt is looped around a similar pulley on your camshaft. As the crankshaft rotates it catches on the teeth that are inside the timing belt and in turn rotates the camshaft. This means that the pistons rise and fall with the turning of your crankshaft, and the valves in your cylinders open and close with the turning of the camshaft.
When your timing belt is working correctly then your piston will rise into the cylinder as the valve opens. At the same time the air and fuel mixture is injected into the chamber where the rising piston compresses it, the spark plug ignites it, and the ensuing combustion reaction forces the piston back down again. This happens across every cylinder in your engine hundreds of times in quick succession to allow your engine to power your vehicle. When any part of this precisely timed reaction goes wrong then your engine will not perform the way it's supposed to and may not even perform at all.
If the timing belt were to break while you were driving, the piston would crash into the valves and cause some severe damage. The valves would bend, it's possible the piston and the cylinder would warp as well, and your engine would fail. The cost to repair it could stretch well into the thousands of dollars.
Fortunately, you can avoid this by maintaining your timing belt on a regular maintenance schedule. There are some signs and symptoms you can be on the lookout for to let you know that your timing belt is going to die, and there is also a suggested lifespan that's going to apply to the specific make and model of vehicle you drive to let you know when you should be having your timing belt changed.
What is the Average Lifespan of a Timing Belt?
Timing belts need to be well maintained to avoid some seriously catastrophic damage to your engine. The absolute best thing that you can do when it comes to understanding how long your timing belt is going to last is to check the owner's manual of your vehicle. It will have the most accurate information for your specific make and model.
Of course, some timing belts get changed at irregular times for unexpected reasons, and it's also very easy to lose track of time over the years. For that reason, it's good to know just in general how long you can expect a typical timing belt to last. More often than not, you're going to hear that a timing belt should last you between 60,000 miles and 100,000 miles. For many drivers that can be about six to 10 years worth of driving, but of course it could be far less if you're someone who drives for a living.
When you look at these specific recommendations for different vehicles this number can change drastically. A Subaru Legacy can last for 105,000 miles before the timing belt needs to be changed. A Volkswagen Jetta can get 120,000 miles. The Toyota Camry only gets 60,000 miles, however.
If you're not sure exactly how long the timing belt in your vehicle has been in place, and you don't have access to the owner's manual any longer then you could definitely Google the make and model of your vehicle to find out for sure, and it's always a good idea to perform regular inspections. Every 30,000 miles give your timing belts an inspection to see how it's doing. That way, even if you're not sure how long the belt has been in place, you should still be able to have some idea how it's doing and not be surprised by a belt that's on the verge of breaking.
How Do I Know if My Timing Belt Has Already Been Replaced?
This is a question that many owners of used cars struggle to answer. You just bought a used car and maybe the previous owner isn't fully aware of the vehicle history. Perhaps they're selling it on behalf of a family member, or it's a car that they've only had for a short time themselves. Maybe you're even picking it up at an auction. So how do you know what the maintenance schedule has been? How do you know if the timing belt was replaced 6 months ago, or it's been in the car for 6 years?
Obviously, the best thing is to make sure you're getting the full-service history along with any used car you buy, including receipts if possible. But that's not always going to be the case. Most mechanics will include a sticker under the hood that includes this information, however. Just like the sticker that you'll get in the corner of your windshield when you have your oil changed, any technician changing your timing belt should be putting a sticker under the hood of your car that lists the date a timing belt has been swapped out. In fact, timing belts and timing belt kits actually come with the sticker as part of the whole package. That doesn't mean every mechanic is going to fill it out, but responsible ones should be doing that and including it where it can be found again by another mechanic or by a car owner who's curious.
Unfortunately, if you don't have a detailed history of your car's repairs then this may be the only way left for you to find out just how old your timing belt is. If the mechanic that swapped out the last one didn't include the sticker, or if it was put on some plays dirty and it ended up falling off then your only option may be to conduct a visual inspection of the belt and use your best guess.
What are the Symptoms of a Bad Timing Belt?
When your timing belt begins to die there are some signs that you can be aware of to let you know it's time to switch it up before a bad situation gets worse. If you're noticing several of these symptoms, it's a good sign your timing belt is having some trouble and it's going to need to be replaced.
Engine Misfires: As we've already established a timing belt is responsible for ensuring that everything in your engine happens right when it needs to. When it's not able to do that job any longer, then your engine performance is going to suffer greatly as a result. That means your timing is going to be thrown off significantly and your engine will experience some misfires.
Essentially a misfire is what happens when the combustion reaction in one of your cylinders doesn't happen when it needs to. Under ideal circumstances it happens just as the piston has fully risen in the cylinder and the combustion reaction will force it right back down again. When your timing belt isn't keeping your camshaft and your crankshaft in sync, then your spark may be trying to ignite the fuel and air mixture at the incorrect time. It's also possible that your valve will not be open when it needs to, or your piston will be in the wrong position at the wrong time. Whatever the case, it's going to cause a drastic drop in your engine's performance because it's not firing when it needs to.
Noises: A malfunctioning timing belt is going to make a fast paced, repetitive ticking noise to alert you to the fact that it's not working the way it should be. This is caused by the teeth on the inside of the belt wearing down significantly and, in some cases, even breaking off. It will be unlikely that you would mistake the sound for any other sound coming from your engine.
Oil Issues: You may have problems with oil leaks and bad oil pressure when there is a problem with your timing belt. This can happen because the bolts securing your timing belt cover come loose and oil will leak around the gasket between the engine block and the timing belt cover. It's also possible that the teeth that come off of your timing belt will fall into the oil pan and clog it, which will in turn greatly decrease your oil pressure. This problem is especially bad because it will also result in your engine overheating.
Check Engine Light: When your timing belt isn't functioning properly and it's disrupting the function of your engine, your check engine light may be triggered as a result. Unfortunately, a check engine light is pretty vague in and of itself so you may need to rely on these other symptoms that was pointed out to let you know that the issue is specifically related to your timing belt and not one of some of the hundreds of other potential reasons that could set off a check engine light in your vehicle.
How Much Does It Cost to Replace a Timing Belt?
The cost of replacing the timing belts very heavily depends on the make and model of the vehicle that you're driving, as well as the mechanic you take it to. Some timing belt replacements could be as cheap as $300 to $500 to get done, while others can stretch to upwards of $1,400 to $2,000. The average does seem to be around that $500 range, but you're definitely going to need to check with few mechanics to get a quote for your specific make and model of vehicle.
The price of a timing belt replacement tends to be high because the job does take several hours to get done and you need to get pretty deep into your engine to perform the task as well. Although it's possible you could try to pull this off on your own, if you're not very skilled at home car repair this job may definitely be too complicated for you to get done.
The Bottom Line
The two clearest methods you have of knowing when it's time to replace your timing belt are your owner's manual recommendations and the signs that your timing belt is going to exhibit when it has begun to wear down and go bad. The best thing you can do is be aware of how long the timing belt has been in your car already, and keep your eyes and ears open for any of the symptoms we mentioned so you know to get your timing belt changed out if and when it's necessary.