Your car’s engine contains many components, one of which is either a timing belt or a timing chain.
Although the timing chain doesn’t get as much attention atims some other car parts, it is extremely important. If the timing chain fails, it can cause an array of problems—including catastrophic engine damage.
What Does A Timing Chain Do?
A timing chain synchronizes the rotation of the crankshaft and camshaft(s) ensuring proper timing and allows the engine’s valves to open and close during each cylinder’s firing.
The chain is located inside of the engine and needs to be lubricated by the oil in the engine, making oil maintenance important as well. Every time you use the engine, the timing chain is in use.
Symptoms Of a Bad Timing Chain
Below are five unmistakable signs that your timing chain may be due for a change.
#1. Rattling Sounds.
A common finding in a vehicle with a bad timing chain is unusual rattling noise when the engine is started or when brakes are engaged. It happens due to the loose or stretched timing chain that shakes and rattles while rotating when the engine motor is running.
#2. Sputtering Performance.
If you notice your car sputtering or hesitating during acceleration, it might be a cue from the timing chain that it’s losing its grip on precision.
A stretched or failing timing chain can throw off the engine’s timing, resulting in a lackluster performance. Pay attention to these hesitations—it’s your engine’s way of asking for a timing chain check or even replacement.
#3. Illuminated Warning Lights.
Just like any other misfunctioning component of the engine, a faulty timing chain will illuminate the check engine light. It is a warning to get your vehicle assessed for underlying engine problems, which might include a bad timing chain.
#4. Engine Misfires.
Timing is everything, and when the timing chain is on its last legs, misfires become a common occurrence.
Misfires, where the engine fails to ignite the air-fuel mixture correctly, can result in poor fuel efficiency, rough idling, and a noticeable drop in power. Treat these misfires as your engine’s way of waving a red flag.
#5. Metal Shavings in Oil.
All metal engine components suffer from wear and tear over time and will slowly degrade. As the timing chain wears, small shavings come loose and will collect in the engine oil. The best way to determine the presence of these shavings (or finings) is to check during an oil change.
In some cases, holding a magnet in the stream of old oil or on a probe into the oil pan will collect visible metal shavings. This should be considered a warning sign that your timing chain is seriously worn and needs to be replaced.
What Causes Timing Chain Wear and Tear?
While every timing chain will eventually need to be replaced if you drive the vehicle enough, there are certain situations and conditions that will accelerate the wear and tear your chain experiences.
In this section, we’ll break those down for you to help ensure that you’re able to maximize chain life and delay any potential damage.
Lack of Oil Changes
Engine oil is responsible for lubricating the moving parts of your engine. That includes the timing chain and the gears/sprockets that it attaches to. If you don’t change your oil on time, this can cause wear and tear and shorten the lifespan of your timing chain.
The problem is that as oil ages, it is exposed to high heat and naturally-occurring detergents from gasoline. These reduce oil’s ability to lubricate (called viscosity).
Your engine oil will also become thicker over time and will coat less and less. Eventually, the timing chain may be left unprotected from metal-on-metal wear. When this occurs, you can expect wear and tear to accelerate dramatically.
The Wrong Engine Oil
Another problem is using the wrong engine oil in your car. While all engine oil types perform the same function, they are not the same. You should use the oil weight recommended by the automaker for your specific model.
This information should be available in the owner’s manual or on the oil filler cap under the hood.
Engine oil is rated by weight, which can be misleading for some. It’s a measure of thickness/viscosity.
For instance, 0W20 flows like 0-weight oil (very thin) during the summer and like 20-weight oil in the winter (thicker). In comparison, 5W20 flows like 5-weight oil in the summer and 20-weight oil in the winter.
Using oil that does not have the right flow characteristics for your engine can mean starving the timing chain of oil or coating it in oil that’s too thick and reducing its performance.
Always use the automaker’s recommended oil for your vehicle. If you’re unsure what it is, ask the mechanic at your next oil change.
Towing/Heavy Loads
The more work the engine must do, the more wear and tear moving parts like the timing chain will incur. This is especially true when it comes to towing or hauling heavy loads. The more weight the engine must move, the harder it must work.
This adds stress and load to the engine and the timing chain. In some cases, you may even hear the chain rattling when the engine is under a heavy load, particularly if the chain is nearing the end of its life.
However, don’t assume that if you don’t hear a rattle your chain is fine. Always follow the automaker’s recommended schedule of services, particularly when it comes to replacing your timing chain.
Failing/Faulty Tensioner
Like the engine’s serpentine belt, the timing chain also has a tensioner. Its purpose is self-explanatory – it provides tension to keep the chain taut and prevent it from jumping. There are two types of tensioner used today: hydraulic and spring-loaded.
If the tensioner fails, it will no longer hold tension on the timing chain. Depending on the situation, this can lead to a rattling sound, but it could also allow the chain to jump and cause the engine to shift out of time. In that case, you may experience backfires and the check engine light will usually come on.
Depending on the situation, this may also cause your engine to idle rough, or put your car into “limp home” mode. This is a security feature that reduces the load on the engine by cutting off nonessential systems, like air conditioning, as well as limiting the speed of the vehicle.
When does a timing chain need to be replaced?
The timing chain normally needs to be replaced between 80,000 and 120,000 miles unless there is a specific problem. Issues with the chain are common in higher-mileage vehicles.
If driving an older vehicle, or one with close to 100,000 miles, it is recommended to look for symptoms of the timing chain going bad or failing.
Since the timing chain can go bad and will need to be replaced, it is important to be able to recognize the symptoms and have it repaired before it fails completely.
Signs a timing chain needs to be replaced include:
- Later model VVT applications will generate engine codes and check engine lights prior to engine rattle
- Older, pre-VVT applications will generate engine rattle
How Much Does it Cost to Get a Timing Chain Replaced?
The cost of replacing the timing chain varies depending on where you’re having it replaced and your vehicle model. Prepare to have a repair budget of around $1,000 to $2,500 for both the parts cost and labor if you’re expecting a timing chain replacement.
If, however, you are the DIY type, you may purchase a timing chain or belt and install it yourself at a price of around $80 to $250. But be aware that some timing chain kits may cost as much as $500 even from the parts store, and are very difficult to replace. A good timing chain kit will come with all the tensioners, the gears, and even a water pump in some cases.
Some timing chains drive the water pump, too, and sometimes the engine must be removed to replace a timing chain. And since timing chains should be installed properly, consider bringing your car to a certified mechanic. There are a lot of other engine parts that must be removed before you even get to the timing chain!
When getting a new car timing chain, most experts recommend soaking it in oil before installing it in the engine to make sure that it’s fully lubricated.
The timing chain is the last to get lubrication upon engine start-up, so this process can help extend the replacement timing chain’s service life.