As part of the routine maintenance for your Subaru, you're going to need to check on the timing chain or the timing belt that is part of your engine from time to time. Just like your other drive belts, your fuel filter, your oil filter, and so on, a timing belt needs to be regularly inspected to ensure it's still working properly. If there's any visible sign of wear and damage, it needs to be replaced before it breaks and causes any more damage. Your Subaru engine will not function properly without a timing belt so you definitely need to make sure you're taking care of it. But what exactly does it do?
What Does the Timing Belt Do in My Subaru?
A timing belt, or a timing chain, is what links your camshaft and your crankshaft together in your engine. The way modern combustion engines work is that, as the crankshaft rotates, pistons will rise in the cylinders of your engine. At the same time your camshaft is rotating which opens the valves at the top of the cylinders to allow the pistons to pass through. Fuel injectors inject the fuel into the combustion chamber, air is mixed with it and then your spark plug ignites to cause a combustion reaction. That forces the piston back down in the cylinder. As this happens in every cylinder of your engine, whether you have 4 cylinders, 6 cylinders, or 8 cylinders, the reaction causes your crankshaft to spin incredibly fast and that energy is transmitted to the wheels of your car which is what allows you to move.
If we back up, the camshaft which needs to rotate to open those valves can only rotate because it's connected to the crankshaft via a timing belt or a timing chain. Because they're connected by pulleys at the end of either shaft, their timing will always be synchronized so this entire reaction that allows your vehicle to work is always precisely timed. Always, unless there's a problem with your timing belt. The belt can wear over time, it has teeth on the inside of it which allow it to hook over those pulleys at the end of the camshaft and the crankshaft, and they can wear down or even break off. The timing belt could stretch out of shape which would cause the rotation of each shaft to be thrown out of alignment, and of course the belts can crack and break over time as well.
In a nutshell, a timing belt is responsible for the timing in your engine which is why it's called the timing belt. If your timing belt isn't working right, your engine could suffer a catastrophic failure as a result. But we'll get into the problems associated with the timing belt in your Subaru breaking down later on. For now, let's figure out whether or not your Subaru has a timing belt or a timing chain because there is a significant difference between the two.
Does My Subaru Have a Timing Belt or a Timing Chain?
Back in the day many vehicles had timing gears or timing chains in the engine. The gears perform the same function as modern belts and chains, but they were just interlinked gears that got the job done. Chains gave way to belts as a number of factors made them more desirable to automakers. Because of the gas crisis and a push to lower the price of automobiles across-the-board, auto makers were looking to save money wherever they could and reduce cost. For this reason, the more expensive timing chains, which were made from metal, were replaced with rubber composite timing belts. Belts became the standard in the majority of cars throughout the 1970s through the 1990s. In the early 2000s the push started to come back from the other direction to return to timing chains.
Because the timing chain is made of metal it is stronger and more durable than a timing belt. In fact, the lifespan of a timing chain could be as much as five times that of a timing belt depending on the vehicle and how it's driven, of course. They’re simply more reliable, and the cost difference really is not that significant.
When it comes to Subaru, many of their older vehicles did in fact run on timing belts however the company started making the move towards timing chains in the early 2010s. By 2013 nearly every Subaru model released featured a timing chain rather than a timing belt.
The Subaru WRX is the only model that retained a timing belt beyond the year 2013, along with the WRX STI. The WRX switched to a timing chain in the year 2014, but the high performance WRX STI model still uses a timing belt to this day.
The WRX STI continues to use a timing belt rather than a chain because it is a high-performance vehicle. That means the engine is typically under more stress than your average engine would be. As a result, it's going to wear it sooner and it's easier to replace a timing belt then a timing chain so it's more of a convenience factor for someone who wants a high-performance vehicle.
What Happens if the Timing Belt Breaks on My Subaru?
If you have an older model of Subaru or you're looking to buy a used Subaru, and it comes from before the year 2013 there's a good chance you're going to have to deal with a timing belt. Now that seven years are past, if the timing belt in it hasn't changed in all that time it's going to be particularly old as well. It will likely be in need of a change in the near future so it's good to be aware of what it means when the timing belt does go bad.
When a timing belt breaks, you have no time to react to the situation. If it happens while you're driving, the crankshaft and camshaft will no longer be linked together. That means the camshaft will stop rotating but the crankshaft will not. As a result, the pistons will rise into the cylinder and crash into the valves which are no longer opening and closing properly. That can cause severe damage to the valves, and may also warp the cylinders themselves as well as the pistons. You can sustain damage to the cylinder heads, gaskets, and more. In the worst circumstances you could require an entire engine rebuild or replacement when this happens. That could cost you anywhere from $4,000 to $5,000 as a result.
When Should a Timing Belt be Replaced on My Subaru?
In general, Subaru timing belts have a fairly long lifespan compared to some Vehicles. A Subaru Legacy lists 105,000 miles as the recommended replacement time for the timing belt in that particular model. For other models the recommended timing to swap out an old timing belt for a new one could be between 60,000 miles and 90,000 miles. Depending on your make and year, you're going to want to check your owner's manual to find out for sure when exactly the timing belt should be changed. And, keep in mind, if a Subaru model still has a timing belt it's probably very close to the end of its recommended lifespan as a result. That means if you're still driving a Subaru with the original timing belt in it, you may be experiencing some of these symptoms of a bad timing belt.
Signs of a Bad Timing Belt in My Subaru
If you're driving an older Subaru with a timing belt then you need to be on the lookout for the signs that it's starting to go bad on you. The last thing you want is for it to break while you're driving, and you'll end up having to pay those costly repair bills we mentioned. With that in mind, you should be on the lookout for the following.
Ticking Sound: The most common sign of a bad timing belt is a ticking sound that comes from your engine when you're driving. The ticking sound is caused by the teeth on the belt as it rotates between the camshaft and the crankshaft. When they have worn down too low, or they have broken off completely the belt will not move smoothly between the camshaft and the crankshaft and the result is this telltale sound, which is kind of like a spinning roulette wheel.
Engine Misfires: Because the timing in your engine is no longer as precise as it should be, you may experience your engine not firing when it's supposed to any longer. These misfires will become worse as your belt stretches out and cracks. Engine misfires can cause damage to your engine as well if they continue to happen on a regular basis as a result of your combustion reaction not happening at all or at the wrong time because everything is not synchronized properly any longer.
Rough Idling: A bad timing belt can lead to situations where your engine seems to struggle even when you're not doing much with it. If you notice the engine sounds louder than normal and it’s vibrating and shaking frequently, even when you're just sitting in the driveway with the engine running, that's a symptom of rough idling and can be caused by a bad timing belt.
Car Won't Start: This is a rare sign of a broken timing belt rather than a failing timing belt. Typically, a timing belt is going to break while the car is in motion and that’s going to lead to the catastrophic failure that we mentioned before. But there's always a chance that the timing belt will break just as you're trying to start your vehicle. The initial stress that you put on the belt as you turn the key in the ignition will cause it to snap and then your engine simply won't start as a result. This is a problem to be sure, but it's actually much more desirable than your timing belt breaking while your car is in motion. This will avoid much of the serious damage that we mentioned earlier.
How Much Does It Cost to Replace the Timing Belt on My Subaru?
The cost of replacing your Subaru’s timing belt could potentially be fairly steep. On average, timing belt replacement costs around $650 to $900 depending on the specific model and year of your vehicle. It's actually cheaper to replace a timing belt on a Subaru than it is in many other vehicles which can sometimes get as high as $2,000.
The reason the repair is so expensive relative to some other issues is because it is difficult to get into your engine and get to the timing belt. Most timing belts are also swapped out at the same time as the water pump because they're located next to one another and it's such an in-depth repair job that mechanics will do them both at the same time. The result is that it typically takes a few hours to get this job done, so the labour costs are considerably higher than they would be for doing something much simpler like swapping an oil filter.
If you're looking to buy just the timing belt itself, there's a range of prices for those as well. For instance, if you head to AutoZone and look for a timing belt for a Subaru Outback you'll find prices that range from $40 to over $300.
The Bottom Line
Even though most Subarus don't use timing belts anymore, if you have an older model then you definitely need to be aware of whether or not it still has a timing belt and how long the timing belt is in place. Given that it's been at least 7 years since most models have been outfitted with a belt, there's a good chance yours is getting close to the end of its life if you still have one. Make sure you are keeping an eye on the belt, how long you've been driving with it, and take it to a mechanic to get it swapped out as soon as you can when you notice signs that there's something going wrong.