So what is a timing chain and how long does a timing chain last? A timing chain as its name suggests is made up of metal links located in a car's engine as part of its internal combustion. Its role is to synchronize various parts of the engine so they can work together. The part can be described as a roller chain with teeth on the inside surface.
If your engine is well-maintained, the timing chain’s lifespan can go up to 300,000 miles or even longer. The chain is specifically installed in the front of the motor and is attached to a set of gears and pulleys that power multiple mechanical components, and that includes the crankshaft and camshaft. In order for your engine to fire, the timing chain must be able to rotate smoothly around the gears without hesitation.
Without it, the crankshaft's movements cannot be transmitted to the camshaft. The metal links allow it to grab onto the different gears and wheels. The engine's valves also manage to open and close at the proper times during each cylinder's intake and exhaust strokes because of the timing chain.
How Long Does a Timing Chain Last: Interference Vs. Non Interference Engine
So what kind of engine do you have? Interference or non-interference? You will need to know because if the timing chain breaks, a non-interference engine will simply fail to start, while an interference engine could carry heavy internal damage.
In an interference engine, the timing chain is also important in preventing the piston from striking the valves. This type of engine is a 4-stroke internal combustion piston engine in which one or more valves in the fully open position are extended into any area through which the piston may travel.
Interference engines are common among modern cars and many other four-stroke engine applications. Examples of cars with interference engines are Audi 1.8L 1.9L & 2.8L V6 90 100 Quattro Interference, BMW 2.5L 325I 525I Interference, and all Acura except SLX Interference and SLX Non-Interference.
This type of engine’s main advantage over non-interference engines is that it allows engine designers to maximize the engine's compression ratio. Using a timing chain instead of gear drive enables engine designers to put the camshaft(s) further from the crankshaft. Also in engines with multiple camshafts, a timing belt or chain also makes it possible for the camshafts to be placed further from each other.
Whereas in a non-interference engine, the piston doesn’t travel into any area into which the valves open. How long does a timing chain lasts is affected by whether or not you have an interference or non-interference motor? With interference engines, the cylinder contains the pistons and valves, but not simultaneously. So a broken chain in this type of engine can result in the parts flying into the cylinder, which can cause severe internal damage.
That wouldn’t happen with a non-interference engine because the pistons and valves are not in the same area. So a non-interference motor provides adequate clearance preventing the valves from hitting the pistons.
Chain complications often cause the links to loosen before breaking, and that breakage can happen while driving or while turning your car on and off. If it disrupts at a low speed, it may just result in a little damage. Running at high RPMs, however, can destroy your engine.
How Long Does a Timing Chain Last: Timing Chain vs. Timing Belt
Timing chains were usually seen on production automobiles from the 1970s to the 1980s when timing belts became the norm. But timing chains have been in a resurgence in recent years. Timing chains as a whole are more durable than timing belts.
So what are timing belts and how is it different from a timing chain? The timing chain as mentioned is constructed of metal and the timing belt on the other hand is reinforced rubber. Belts are quieter and because of their material are cheaper to produce. Timing chains on the other hand are housed within the engine and can receive lubrication from engine oil so it can last a long time. Whereas timing belts are located outside of the engine and can dry out and crack.
Since the introduction of the internal combustion engine, a timing chain or timing belt has been in use. But most higher-displacement engines have a timing chain as opposed to a timing belt. More vehicle manufacturers have integrated timing chains back into some vehicles with impactful improvements such as noise and vibration reduction. Different from a timing belt, not all water pumps are driven by the timing chain. But neither the timing chain nor timing belt is as durable as the gear drive. So when asked how long does a timing chain lasts, the answer is longer than a timing belt but the gear drive will still last longer.
How Long Does a Timing Chain Last: What are the symptoms of a bad timing chain?
A timing chain is indeed made out of metal, but it is still subject to wear and tear over time and may eventually break if not replaced as recommended by the manufacturer. The wear and tear will cause the engine's timing to be inaccurate and here are the symptoms to watch out for:
As evident in this article, there are two ways in achieving the proper valve timing in a combustion engine. One is the two-gear method and the other one the timing chain method. The first method includes the crankshaft to camshaft gear direct connection, which is used in most types of heavy equipment and big trucks. The timing chain method, on the other hand, is more commonly used in consumer vehicles and high-performance engines.
The timing chain, on the latter, can eventually stretch causing the chain to skip a gear on the cam or crankshaft. When this happens the engine’s timing falls out of calibration and will often result in an engine misfire. The engine runs poorly and lacks accelerating power.
These symptoms, showing that the timing chain might be damaged entails that the timing chain needs to be replaced immediately. Don’t wait for the timing chain to break as the loose metal rolling around inside the motor can lead to serious engine damage.
- Engine won’t start or fails
A damaged timing chain will also cause an engine to fail to start or failing while driving. A broken chain or belt will cause the engine not to have enough compression to start. Even worse is the fact that If it breaks or jumps while you are driving the pistons will also be damaged from contact with the valves.
If the valves themselves bend it can potentially ruin the engine. If the belt also jumps because it’s gotten loose, it can also flail around damaging other parts of the engine. So if your engine won’t start or starts to drive rough look into those timing chains or timing belts as they may already be damaged.
- Engine clanking while idling
How long does a timing chain last can also become evident with the sounds you hear from your engine? Strange sounds are a common symptom of a problematic motor. Under normal operations, the engine will have a consistent and smooth sound that indicates everything is running as it should. But when the timing chain becomes loose, it will cause a vibration inside the motor producing clanking or other strange noise as the engine idles. Anytime you hear a strange noise it might mean something has become loose and will need to be fixed before it gets broken.
The noise from the timing chain is commonly most noticeable during cold startup when the oil pressure and the oil flow are at their lowest. Excess slack in the timing chain can also cause a clanking or even a rattling sound if the slack is severe enough to cause the chain to contact the timing chain cover.
If your engine comes equipped with a hydraulic timing chain tensioner, then the noise may disappear or lessen as the engine oil warms up and the tensioner manages to remove some of the slack. But if the timing chain has worn out severely enough the tensioner will no longer be able to compensate for the slack and the noise may just continue even after warming up.
- Metal shavings found in the oil
All car manufacturers recommend changing the engine oil and filter every 3,000 to 5,000 miles because over time the oil will start to separate as it heats up and is exposed to natural solvents present in gasoline. Small metal pieces can break off the chain if the timing chain begins to wear out and those metal pieces will find their way into the oil pan.
So when you have your oil changed, and the mechanic informs you that they found small pieces of metal inside the oil as it drained or in the filter, it can be a good indication that your timing chain is already beginning to wear out. The metal shavings can also be commonly seen when there is extensive wear to your cylinder head valves, retainers, keepers, and other cylinder head hardware.
- Check Engine Light is on
One reason a check engine light illuminates among a variety of causes is a failing timing chain. The car’s computer will display warning lights and they must be checked and scanned for trouble codes to find out exactly what is wrong. The check engine light may light up when the onboard computer detects something wrong with the engine operation or with the emissions system.
How Long Does a Timing Chain Last: Frequently Asked Questions
Can a timing chain be tightened?
Timing Chain or Timing Belt Tensioners tighten the timing chain automatically and if the chain has become so loose that the tensioner can no longer tighten it anymore, then the only option left is to replace the chain. It is also recommended that while you are having it worked also replace the tensioner, sprockets, etc. It's also a good idea to replace the water pump for some vehicles during the timing chain replacement as most of the parts that are removed to replace the chain will have to be removed for the water pump replacement as well.
How much does it cost to replace a timing chain?
Replacing the timing chain is a difficult and complicated job, and it goes to say that the labor costs can be quite pricey. So for most vehicles, a timing chain replacement may cost between $413 and $1040. If you choose to order the parts yourself it will only cost between $88 and $245. But remember, it is a tricky and complicated repair so unless you’re really particularly skilled then it’s still best to get assistance from a reliable mechanic.
Final Words…So how long does a timing chain last?
In a perfect world, where one executes perfect maintenance work and oil is changed on a regular basis, the timing chain should last the lifetime of the engine. But usually, the timing chain by average will need to be replaced after going 80,000 to 120,000 miles unless you encounter an untoward problem.
Timing chain premature wear is common among higher mileage vehicles. If you are driving an older vehicle, or a vehicle with close to 100,000 miles, it is recommended to watch out for symptoms of a failing timing chain.
Other signs a timing chain needs to be replaced already include engine rattle for older, pre-VVT (variable valve timing) application and generation of engine codes and check engine lights lighting up for later models with VVT applications.
A stretched or worn-out timing chain causes poor engine performance and increased emissions, triggering for the check engine light to illuminate and generate a diagnostic trouble code. A mechanic will be able to inspect the code and prescribe the right needed repairs.
In the absence of a working timing chain, being a major component of any engine, your vehicle will not run at all and become useless. Again, if the timing chain breaks as you drive then serious damage to your car's engine is a strong probability.
The surest and best way to reduce the potential for serious engine damage is still to have a professional mechanic replace your timing chain. So if you observe any of these warning symptoms listed above have your timing chain checked immediately. You can save yourself not only from the stress but also thousands of dollars of expense by significantly extending the life of your car’s engine from preventing it from serious damage.