The functionality of an internal combustion engine depends on its valves to open and close at the proper times. Each time you apply pressure to the gas pedal with your foot, it puts more demand on the engine to generate power.
This demand influences the timing of the movements associated with the valves and pistons. However, the valves and the pistons cannot coordinate their actions without the assistance of a vital component called a timing chain.
What Does a Timing Chain Do?
A timing chain is responsible for synchronizing the rotation of the crankshaft and camshaft so that the valves can open and close at the correct times. It also stops the pistons from making contact with the valves too. The valves and pistons allow fuel to enter the engine’s cylinders for the combustion process to occur.
The timing chain runs over a series of gears to move the valves and pistons at the precise time they’re supposed to so that the engine can receive the fuel it needs. But if the timing is off, it could damage the engine and cause many other problems for the vehicle.
Bad Timing Chain Symptoms
Your vehicle cannot function without a strong timing chain. Unfortunately, a timing chain suffers wear and tear whenever you drive your car. It could also suffer damage if you got into a car accident or experienced weather-related car damage.
It will be easy to figure out when your timing chain is starting to wear out because you will notice specific symptoms that are unusual and affect the vehicle’s functionality. If you don’t replace your timing chain quickly, it could end up breaking or snapping altogether.
Once that happens, it will render your vehicle undrivable and may even cause permanent damage to your engine. Then you’ll have to pay thousands of dollars to replace it. So don’t wait for that to happen.
Here are the top 5 symptoms associated with a bad timing chain.
1) Engine Misfires
An engine misfire happens if at least one cylinder cannot complete the combustion process and produce power for the vehicle. Many things can cause an engine misfire, including a worn-out timing chain.
When a timing chain gets old and worn out, it becomes too weak and stretched out. Eventually, the timing chain will start to miss some of the gears as it runs over them. That is what will cause an engine misfire to happen because the crankshaft and camshaft will lose their coordination with each other.
If you’ve experienced more than a few engine misfires, then it is likely due to a timing chain problem. The best solution is to replace the timing chain before it causes you to get stranded or the engine to suffer irreversible damage.
2) Poor Acceleration
When a worn-out timing chain affects the engine, you’ll immediately experience a weaker performance from your vehicle. Suddenly, you won’t be able to accelerate the car as quickly when applying pressure to the gas pedal. The weak engine performance will translate into poor acceleration.
Don’t keep driving your vehicle if it cannot accelerate efficiently. Otherwise, it will put too much stress on your engine and cause it to get damaged too quickly. Instead, it is best to bring your vehicle to an auto mechanic to replace the timing chain.
3) Strange Sounds
A timing chain loosens as it becomes weaker. If a weak timing chain runs over the gears, it will produce vibrations and rattling sounds. You may even hear these sounds more while the car is parked and the engine is idle.
The rattling sounds will come and go at first. But as the timing chain develops more loose parts, it will cause more rattling sounds for extended periods. What’s worse is these loose parts could severely damage the combustion system and engine.
So if you hear rattling sounds coming from your engine, investigate the problem immediately. If the cause turns out to be a bad timing chain, replace it before driving your vehicle again.
4) Check Engine Light
The “Check Engine” warning light on your dashboard should turn on as your engine experiences these issues. But if the warning light is the first symptom you notice, the nature of the problem won’t be immediately clear to you.
There are a few ways you can confirm the cause of the warning light. First, you could run a diagnostic check on the engine control unit to try and pinpoint the problem. But if that doesn’t work, bring your vehicle to an auto mechanic and have them diagnose the problem for you. If they determine the timing chain is the cause of the warning light issue, then replace the timing chain.
5) Metal Shavings in the Oil
When the timing chain continues to wear out, small pieces of metal shavings will start to mix with the engine oil. You won’t notice the problem unless you inspect the oil filter and engine oil for signs of these small metal pieces. If you see them stuck in the oil filter, then a bad timing chain is likely the cause of it.
Have an auto mechanic confirm the cause of the metal shavings. Even though a worn-out timing chain is likely the cause, it never hurts to get a second opinion from a professional before spending the money to replace the chain.
Timing Chain Replacement Cost
It is expensive to replace a timing chain. That is why you should only do it if you have no other choice. The average timing chain lasts about 100,000 miles before it needs to be replaced. If your vehicle has over 100,000 miles and experiencing any of the symptoms mentioned above, then it may be time to invest in a replacement timing chain.
The cost of the timing chain part is between $100 and $300. However, the more significant expense is associated with the labor costs because it is complicated to access the timing chain. The procedure may require 1-4 hours, which means the auto mechanic fees will add up fast. You can expect to pay anywhere from $100 to $400 for the labor.
Therefore, the total replacement cost of a timing chain is between $200 to $700. Of course, the actual price depends on the make and model of your vehicle. It is easier to access the timing chain in some model vehicles versus others.
Job Description of Replacing Timing Chain:
- Remove all drive belt and tensioner
- Remove other parts that block timing chain cover
- Remove valve cover
- Put crank shaft and camshaft on TDC
- Remove crankshaft pulley
- Remove timing chain cover
- Remove old timing chain
- Fix new chain
- Make sure the timing in correct position
- Using a sealant fix timing cover
- Fix crankshaft pulley
- Fix valve cover
- Fix other parts that block timing chain cover
- Fix tensioner and engine belt
Conclusion of Timing Chain Replacement Cost
- Estimate taking time: 1-4 hours job, that mean $100 – $400 labor cost
- Estimate part: $100 – $300
- Estimate timing belt replacement cost in total (part & labor): $200 – $700
The cost estimate of labor and part may vary depend on the car type, brand and model. Some model easy to replace and some model very hard to replace.
Causes of Timing Chain Noise
A bad timing chain is not always the cause of timing chain noises. It is undoubtedly the primary cause, but there could be other possible causes of the noises too.
Let’s take a look at some of the primary causes of timing chain noise:
- Wear and tear on the timing chain
- Bad oil filter
- Old engine oil
- Wrong engine oil
- Your vehicle is carrying too much weight (heavy load)
- Bad tensioner
A tensioner allows the timing chain to have the proper amount of tension over the gears. But if the tensioner goes bad, the hydraulic component or spring used to produce the tension will suddenly stop functioning correctly.
As a result, the timing chain will no longer have the proper tension. That will lead to all the other symptoms mentioned above, such as the check engine light turning on and engine misfires.
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Timing Belt vs. Timing Chain
Some automobiles use timing belts instead of timing chains, but they both serve the same purpose. A timing belt is a flat and sturdy rubber belt with a series of teeth on one side. These teeth allow the belt to run over several different pulleys inside the engine.
A timing chain looks different because it has several sturdy links in them. It is similar to the appearance of a bicycle chain, but it is heavier and more sophisticated. The timing chain is inside the engine and runs over its gears to make them move smoothly. The engine oil keeps the timing chain lubricated as it flows through the engine.
Timing chains are stronger, heat resistant, and have more longevity. The only maintenance needed is regular oil changes for the engine. On the other hand, timing belts are lighter, cheaper, fuel-efficient, and less noisy. But the problem is they are weaker and wear out faster. That is why timing chains are still preferred in modern vehicles over timing belts.