Most folks tend to overlook a few car components, and one of such parts is the timing chain.
A defective timing chain can cause some serious damage to the engine and decreases its performance. However, you would notice some symptoms of a bad timing chain before a complete failure.
Most experienced drivers know that their car’s internal combustion engine uses either a timing chain or belt. Nevertheless, the timing chain is often present in high displacement engines, as they get attached to a set of pulleys and gears.
The timing chain must move the camshaft and crankshaft smoothly before the engine fires. So, the engine won’t start if the timing chain wears out or breaks. You may be wondering what causes the chain to break if it is made of metal and appears strong.
Well, the metal-to-metal contact and other external factors can cause the timing chain to wear over time. Not to worry, the system gives off some signs that hint you at the lingering danger to allow you to replace the worn chain on time.
What is a Time Chain in a Car?
So, before we dive into the timing chain symptoms, let’s first cover some of the basics and learn what is a timing chain in general.
This would be quite useful for beginners that are not into mechanics and can’t tell if their car is running a belt or a timing chain or maybe none of the two mentioned.
If you are feeling that you know this stuff, you can just jump on the causes or the timing chain symptoms. If not, keep up with us for a bit.
Before we learn what is a timing chain we need to understand what are interference engines and what are non-interference engines.
Interference engines are the ones that have the camshafts located on the top of the engine head. Also known as overhead camshaft engines.
In order for these engines to work properly, they have to have proper timing. If they don’t they would suffer internal damage. Meaning that the valves and the pistons will collide and cause carnage.
Non-interference engines on the other hand are engines like the classic pushrod V8s that are still widely used.
On these engines, there is a chain, but this chain is not a timing chain. Even if this chain breaks or gets stretched, the engine will keep working and no damage will be done to it.
So, if you are trying to learn the timing chain symptoms, you probably have an interference engine.
These interference engines are also using timing belts. In fact, most of them are running these belts. But some, mostly the engines on the more expensive cars are running timing chains.
The timing chains are known for their durability but still have to be replaced when timing chain symptoms start to show up.
Types of Timing Chain
Now that you know the role of a timing chain, let us discuss the two types of chains used by car producers. For each type of chain, there are different timing chain failure causes resulting from the specific build of the component.
#1. Link Chains.
This type of timing chain is made of precision links made of flat hardened alloy steel. They are connected to each other by pressed pins.
This is also known as a silent chain because its shape is designed for smooth operation. We mention this because if you happen to hear noises, then you definitely have timing chain issues.
#2. Roller Chains.
This type of chain looks very much like the one you find on a bicycle. But, of course, it is made much more durable and resilient. Cars with a smaller engine capacity have a single roller chain. More powerful engines require a double chain.
As we are speaking of timing chain symptoms, do not confuse it with a timing belt. While it serves the same purpose, it is a completely different component and has specific signs of failure.
What is the Timing Chain in Bikes?
Timing chains are not only present in car engines but also in motorcycles. The small roller chain, which seems like the regular bicycle chain, appears to be the timing chain of your bike’s engine.
This chain drives the camshaft that sits atop the engine; hence, it is called the ‘cam’ chain. Nevertheless, some bikes do not have the timing chain but utilize belts and gears for driving the camshaft.
Like cars’ engines, the motorcycle engine has valves that take care of the cylinder’s gas exchanges.
These valves can only open or close with the help of the crankshaft. You would find the timing chain of your motorcycle connected to the crankshaft and the camshaft. The basic appearance has the timing chain connected to the sprockets.
Kindly note that the larger sprockets mount on the camshaft while the smaller sprockets mounts on the crankshaft. Like what happens in cars, the crankshaft movement drives the chain of the bike’s engine.
Then, the timing chain gets the camshaft in motion, causing the valves to open and close. There is also a timing chain tensioner with a slider or wheel, which supplies enough pressure for proper chain movement.
In essence, the tensioner supports the chain and removes any excessive slack. Thus, you should look out for symptoms of bad timing chain tensioner in motorcycles if the timing chain system won’t function properly.
How a Timing Chain Works?
Timing chains work a bit like bicycle chains. If you’ve ever ridden a bicycle, you know that the chain connects the pedals to the rear wheel. As you push, the torque from the pedals is transferred to the rear wheel using the chain.
On a four stroke engine with a timing chain, the crankshaft’s rotation is transferred through the chain to the camshaft(s). The timing chain’s job is to keep the crankshaft and camshaft(s) precisely synchronized so the engine’s valve timing stays accurate.
This synchronization allows the valves to open and close at precisely the right time relative to piston movement, allowing the engine to draw in air-fuel mixture and expel exhaust gases efficiently.
Why Is The Timing Chain So Important?
Now before we cover the causes and timing chain symptoms, let’s discuss why the timing chain is important? What is so crucial about the timing chain that makes it an irreplaceable component on your car?
The answer is simple, the timing chain is connecting the camshaft or camshafts that are located on top of the engine with the crankshaft which is located in the center of the engine.
When the camshafts start spinning at the top, the valves open and close. Thus, allowing fuel and air to be inserted into the engine and the exhaust gases to be released from the exhaust valve.
If there is nothing there to open and close these components, the engine will simply not work. That’s why the timing chain is so important. Without a timing chain, the internal combustion engine will be incomplete and you will not have a combustion process.
So, you can understand how crucial is this timing chain on your car. Sadly though, even though the chain is really strong and can withstand a lot, it can still fail and cause a number of problems on your car.
What is important for you is to learn the timing chain symptoms that we are going to discuss later in the article and based on these symptoms you to be able to tell if your timing chain is done and needs replacing.
What is good though, is that the timing chain is not so sensitive as the timing belt that can snap and destroy the engine.
Usually when the timing chain is going bad, is developing timing chain symptoms. But what are the causes for this timing chain going bad? Let’s elaborate on them in the following chapters.
Symptoms of bad timing chain
Unlike timing belts, the timing chains of engines appear to have a longer shelf life. Nevertheless, it is common for things to wear with constant use. The accumulated wear of over 150,000 miles of drives can cause some serious damage to the timing chain.
Some experts reveal that car owners should schedule maintenance after 120,000 miles to avoid a faulty timing chain. However, this speculation varies from car to car, and the extent of the wear would depend on the car use.
Still, a loose or broken timing chain spells huge trouble, as it could cause some damages to the pistons and valve. Undoubtedly, such damages can also cause the engine to fail, incurring a new car engine cost.
Thus, try to look out for possible signs that tell you the timing chain is in bad shape. Ignoring the glaring symptoms of a bad timing chain can be disastrous. With that in mind, the following are some symptoms of a faulty timing chain.
#1. Timing Chain Disengaging from the Tensioner or its Idler.
The timing chain tensioner provides the chain with sufficient pressure for proper movement.
Thus, the car’s engine would come to a halt when the chain disengages from the tensioner. You would start hearing an audible grinding or clattering sound before the engine completely stops.
This sign seems common and can notify you when the chain jumps off a single sprocket. It is imperative to take such symptoms seriously and take the vehicle to an expert mechanic.
#2. Check Engine Light.
The CEL warning on your vehicle’s dashboard often comes on when there is an engine problem. As mentioned above, a faulty timing chain would mean serious trouble for the engine.
Either the exhaust emission exceeds speculations, or the system exceeds the preset limits of the valve timing.
By now, you should know that the opening and closing of the valve are under the control of the timing chain and tensioner. So, when the check engine light illuminates, it could be a sign that the engine chain is wearing out.
This sign is also one of the symptoms of a bad timing chain tensioner. In most cases, both the tensioner and chain wear out simultaneously; hence you should replace both when the need arises.
Nevertheless, there are a plethora of issues that could make the check engine light come on. So, you may want to conduct further diagnosis using the OBD2 scanner. This diagnostic tool would reveal a code that tells you whether or not the timing chain is in bad shape.
#3. Rattling Sound.
Various strange noises seem pretty audible when the timing chain is bad. You would often hear such weird noise when you turn on the engine and warm up the vehicle. Nevertheless, the sound starts to fade off after the engine warms up.
#4. Metal Shavings in the Motor Oil.
It seems very common for metal pieces from a breaking timing chain to make their way to the oil pan. Thus, if you change your car’s oil frequently (between 3,000 to 5,000 miles as recommended), you would notice the metal shavings.
When you change your vehicle’s oil, please do not ignore the metal shavings around the filter or in the oil itself. It is a significant sign that tells you if the cylinder head valves are wearing out due to a faulty timing chain.
#5. Engine Misfire.
When the timing chain appears broken, it is normal for the valve movement to stop or face some disturbances. Thus, they wouldn’t open or close at the right time to match the rising and falling of the pistons.
When such a situation occurs, the engine’s cylinder would not have any combustion and the engine misfires.
This problem is quite alarming, as it can create an unbalance in the air-fuel mixture ratio. So, you can find the vehicle’s engine sputter, and you may experience a rough ride.
#6. Engine Won’t Start.
Have you ever experienced that the car wouldn’t start? It could be due to some lousy starter problems. However, if you notice that the vehicle delays to start or wouldn’t come on even when the starter motor engages, the timing chain may be in bad shape.
The engine components won’t move properly with a broken chain, and the engine won’t turn on.
This problem may cause the engine to halt while driving, and it is pretty dangerous. In extreme cases, the pistons may get damaged as they meet the valves, and the valve would also get bent.
#7. The Timing Chain Stretches.
The constant use of the timing chain makes it start stretching with time. This wear results from the constant work the chain does in moving the engine parts. With that, the timing of the valve’s movement would degrade, causing some other issues.
Hence, the car would start consuming more fuel, and there would be increased roughness, accompanied by low engine powering while driving at low speeds. Supposing the timing chain of your vehicle stretches, you would also hear an unusual rattling sound.
If you take note of one or a combination of these signs in your vehicle, then the timing chain seems faulty. Kindly ensure that you find a solution as soon as possible. Do not wait till the engine fails before contacting the mechanic.
What Causes a Timing Chain to Break?
#1. Neglected Oil Changes.
The most common cause of timing chain failure is neglected oil changes. Old, dirty oil can clog or restrict the oil passages that feed the hydraulic timing chain tensioner.
When the tensioner can’t maintain proper oil pressure, slack develops in the chain. This leads to increased wear, rattling noises, and eventually may cause the chain to snap.
#2. Low Oil Level.
Even with fresh oil, running your engine with low oil level can starve the timing chain tensioner of lubrication.
Hydraulic tensioners rely on proper oil pressure to function. If the oil level drops too low, the oil pump may not maintain adequate pressure at the tensioner, allowing the chain to run loose and wear prematurely.
#3. Bad Timing Chain Tensioner.
A bad timing chain tensioner will lead to a loose timing chain. This puts a dynamic load on the chain as you start and stop the engine, increasing wear if it exceeds the tolerances the chain was designed for.
Tensioners can fail due to worn springs in mechanical types or failed seals in hydraulic types.
#4. High Mileage Wear.
While timing chains are designed to last the life of the vehicle, this doesn’t always hold true for high-mileage engines.
Vehicles with over 200,000 miles may experience chain stretch from years of use. The chain pins and links gradually wear, causing the chain to elongate and eventually fail.
#5. Wrong Oil Viscosity.
Using the wrong oil viscosity can affect hydraulic tensioner operation. If you use oil that’s too thin or too thick for your engine, it may not provide adequate pressure to the tensioner.
Always use the oil weight specified in your owner’s manual to maintain proper timing chain tension.
#6. Broken Timing Chain Guide.
A broken timing chain guide may allow the chain to move out of position. This can cause the chain to jump teeth, skip timing, or in severe cases, come off the sprockets entirely.
Guide failure is often the result of age, heat deterioration, or prolonged contact with a loose chain.
#7. Manufacturing Defects.
Some engines have known timing chain problems due to manufacturing defects or design flaws.
Certain Ford 5.4L 3-valve engines, various Nissan VQ engines, and some BMW models have documented timing chain issues. If you own one of these vehicles, you may need to replace the timing chain earlier than expected, even with proper maintenance.
How to Diagnose a Bad Timing Chain?
Finding a timing chain issue needs careful checks. Some you can do at home. Others need special tools.
#1. Simple DIY Checks You Can Do.
You can do some checks at home:
- Listen for rattles when you start the car
- Look for metal bits in your oil
- Use a code reader to check for timing codes
- Watch how your engine runs at idle
These checks can hint at problems. But they aren’t final. If you think you have chain issues, see a pro. They can confirm the problem.
#2. Professional Diagnostic Methods.
Pros have many ways to check timing chains:
- Use a camera to look at the chain
- Measure how much the chain has stretched
- Check timing with a special tool
- Test engine compression for timing issues
These methods give better answers than home checks. They show how bad the problem is. If you have chain symptoms, a pro check is worth it. It can save money later.
#3. Common OBD-II Codes for Timing Chain Issues.
Bad timing chains often trigger specific codes. The most common are:
- P0016: Cam and crank timing off (bank 1, sensor A)
- P0017: Cam and crank timing off (bank 1, sensor B)
- P0018: Cam and crank timing off (bank 2, sensor A)
- P0019: Cam and crank timing off (bank 2, sensor B)
If your tool shows these codes, the chain is likely bad. This is very true if you have other symptoms too.
How to Address a Failing Timing Chain?
If you suspect your timing chain is failing, it’s crucial to act quickly. Here’s what you should do:
#1. Inspect the Timing Chain.
If you hear unusual noises or notice other symptoms, have your car inspected by a qualified mechanic. They can visually check the timing chain for wear or damage.
#2. Replace the Timing Chain.
Replacing a timing chain is a complex job that typically requires professional assistance. The cost of replacement varies depending on the make and model of your car, but it’s worth the investment to prevent further damage.
#3. Check Related Components.
When replacing the timing chain, it’s a good idea to inspect and replace related components such as the tensioner, guides, and sprockets. These parts ensure the chain operates smoothly and lasts longer.
#4. Maintain Regular Oil Changes.
To extend the life of your new timing chain, follow the manufacturer’s recommended schedule for oil changes. Clean oil keeps the chain lubricated and reduces wear.
Preventing Timing Chain Failure
Preventing timing chain failure is crucial to avoid costly repairs and ensure the longevity of your engine. Here are some tips to help you prevent timing chain failure:
- Regular maintenance, including oil changes and inspections, can help to identify potential problems before they become major issues.
- Replacing the timing chain at the recommended interval can help to prevent wear and tear.
- Monitoring engine performance and addressing any issues promptly can help to prevent further damage.
- Using high-quality engine components, including the timing chain, can help to ensure reliable performance and prevent premature failure.
How Much Does It Cost to Replace a Timing Belt?
A timing belt service is more than just the belt itself. While traditionally, everyone thinks of this change as “just the belt,” it is not.
A timing belt is tensioned and held in the proper track by a series of tensioners and idler pulleys, all of which have bearings and the ability to fail.
Likewise, many vehicles have a water pump that is driven by the timing belt. In these cases, it makes complete sense to change the water pump with a new unit at the same time, since the labor to expose the pump is being completed anyway.
There is nothing worse than paying for a timing belt service, declining the water pump replacement for an additional $100, only to find out 6 months later that the water pump is leaking, and now everything must be replaced again.
In most cases, a timing belt kit will consist of the belt itself, 2-3 idler pulleys, and a tensioner. When the job is done, all these components will be changed out. In most cases, a timing belt kit will run between $100 -350.
Labor on most timing belts is between 3-5 hours, putting your total cost between $400 -1,000. Remember, do not opt for a “just the belt” replacement. While the cost is cheaper, the chances of further failure increase significantly.
If the water pump is being done at the same time, the labor should be minimal, and less than 1 hour, as the work to expose the water pump and remove the timing belt is being done anyway.
If you decide to do the job yourself, make sure you follow each step of removal and reassembly perfectly, and research as much as possible on the job.
Many timing belt jobs require the camshafts to be held in place by a special tool – do not let this scare you. While these tools are readily available, many of them are vehicle specific, so there can be a multitude of them.
Many other tricks are shown online on how to keep the camshafts properly in place when installing the new belt, and many more do not require any tools for this at all.
Remember that once the new belt is in place and properly tensioned, always rotate the engine slowly by hand, checking and double-checking the belt alignment and make sure everything looks proper. If any resistance is encountered, stop! Recheck the alignment.
Remember, if your timing belt breaks, the damage is much, much worse. At this point, the cylinder head must be removed, valves replaced, or new remanufactured heads installed. This takes that timing belt job from $400 -1,000 and just raised it to $3,000 -5,000.
In many cases, repairing a timing belt breakage is so expensive it is more than the value of the vehicle.
FAQs.
Q: What does a bad timing chain sound like?
You are often likely to hear a rattling sound from the engine when the timing chain is faulty. As you try to warm up the car, you would hear the weird sound, and after the car warms up, the sound may start dissipating.
In most cases, it may be due to a loose timing chain, as it collides with the other components of the vehicle’s engine. Again, such sound could be one of the ‘timing chains off a tooth’ symptoms or a sign that the chain is wearing out.
Q: What happens when the timing chain goes out?
When the timing chain goes off, the engine won’t start even if the car starter motor engages.
This problem occurs since the engine lacks sufficient compression required for it to get the car started. If you’ve been driving and the chain suddenly goes out, the engine may fail.
With such a situation, the engine’s pistons would get damaged as they meet the valves. Also, you would notice that the valve would appear bent from such effect, causing further damages that may ruin the engine completely.
Q: How do you know if your timing chain is stretched?
If the timing chain appears stretched, then the car’s engine would run rough on idle or during acceleration, and you may notice the check engine light turning on. One significant thing that could also occur is the car losing power without any warnings.
With then stretch, the chain may start hitting the cover, and as such, you may hear some weird noise from the engine. It is crucial to fix such a problem on time, as a stretched chain can easily skip a gear, creating an improper timing calibration.
Q: How long will a bad timing chain last?
The timing chain often lasts for a long period, between 40,000 miles and 100,000 miles. The design of the chain is durable, and as such, they last longer than the timing belts present in some vehicles.
Thus, there may be no need to change the timing chain until after this duration. Nevertheless, some external factors may cause the timing chain to wear out sooner than expected.
When replacing the timing chain, kindly ensure that an expert mechanic handles it, as the process seems pretty complicated.
Q: Can you tighten a timing chain?
Adjusting the timing chain is possible, as you can either tighten or loosen it to create a synchronized movement within the engine. Performing such action can cause the chain to move well with the timing chain tensioner.
The excessive pressure on the timing chain can often cause it to slack; hence, the need for adjustments. Before you think of tightening the chain, you should first consider the needs of the gears connected to it.
Q: Will the check engine light come on for the timing chain?
When the timing chain fails, the check engine light turns on. By now, you should know that the light illuminates on your dashboard when the vehicle’s computer finds something wrong with the engine.
However, it seems challenging to know the exact reason behind the light when it appears, as various issues could be wrong with the engine’s operation.
It could be due to a faulty spark plug or even a low oil pressure. Thus, you should use an OBD2 scanner to tell if the timing chain system is in bad shape.
Final Words
The timing chain plays a significant role in the engine’s proper functioning, as it synchronizes the movement of the valves with the motion of the pistons.
However, a failing chain can cause some serious problems for the engine and the overall functioning of the vehicle. Knowing how to check for a bad timing chain may seem like a daunting task.
Hence, it is crucial to learn about the symptoms of a bad timing chain. With these signs, you can easily sense the danger and fix the issues with the timing chain system on time. Thus, you can prevent further damages to the engine and make the car perform optimally.