Failing Timing Chain Symptoms, Diagnosis, Cost & Replacement Guide
Date Posted: 4 August 2020
So, how does the timing chain work, and what happens if it fails?
This article will guide you through everything that you need to know about your timing chain. Once you follow all these guides, you will be able to diagnose and quickly know when to schedule a replacement.
What does a timing chain do?
An engine's timing chain keeps the movement of the components in the top half of an engine in sync with those at the bottom. It specifically synchronises the rotation of the crankshaft and camshafts, making sure that the timing is perfect with the engine's valves as it opens and closes during each cylinder's firing.
Timing chains made a comeback over the past couple of decades because of its durability. It has replaced the timing belts, which were used during the mid-80s through the 2000s as drivers wanted a much quieter engine. But as time wore on, however, timing chains were used once again as they found that timing belts tend to be more problematic.
How long will a timing chain last?
The timing chain needs typically 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. It is advisable to look for symptoms of the timing chain going bad or failing, especially if you are using an older vehicle model, one with close to 100,000 miles.
Also, it is crucial to recognize the symptoms and have it repaired before it fails since the timing chain can go wrong and will need to be replaced immediately.
What are the symptoms of a bad timing chain?
Unlike timing belts, timing chains tend to give more warnings before they fail. Timing chain belt warning signs should not be ignored; that's why we have listed below five timing chain symptoms you can look for. Should you notice any of these timing chain warning signs, we recommend contacting your mechanic as soon as possible. They are the best ones to diagnose what the cause is and make the best recommendation on how to repair it.
Engine misfires or runs poorly
A combustion engine provides two ways to achieve perfect valve timing. The first one is the two-way system in which it involves a direct connection of the crankshaft to the camshaft gear. This is used mostly in heavy machinery vehicles and large trucks. The second one is the timing chain system, which is most common in high-performance engines and commercial vehicles.
Although it can extend over a while, timing chains can still cause the chains to skip a gear onto the camshaft or crankshaft. This causes the engine's timing to fall out of sync that could sometimes lead to a misfire. Also, the engine could run poorly and could lack accelerating power.
If this happens, it is likely that the timing chain is broken and needs to be replaced as soon as possible. If the timing chain breaks, the engine might get severely damaged resulting in the loose metal rolling inside the motor.
Metal shavings found in the oil
All automakers suggest changing the engine oil and filtering every 3,000 to 5,000 miles. Over time, the vehicle's oil tends to separate as it heats up and gets exposed to other natural gasoline solvents. If the timing chain starts to wear out, small pieces of metal can break off the chain and find their way into the oil pan.
If you have your oil changed and the mechanic tells you that there were small pieces of metal inside the oil as it drained or filtered out, it usually is a good factor that your timing chain might start to fail. Metal shavings can also be found when the cylinder head valves, keepers, retainers, and other hardware are worn out heavily. This is very important to have a mechanic inspect it and repair it as soon as possible.
Engine won't start or fails
If you are having timing chain problems, this usually means that you won't be able to start your vehicle. This is because the engine won't have enough compression to operate. If it jumps or breaks while you are driving, what happens usually is that the pistons will be damaged from contact with the valves. The valve will then bend itself and potentially destroy the engine.
If your engine has a hard time starting or is rough when driving, it usually indicates that maybe it is on its way to having a significant problem. It is advised to seek your local mechanic immediately and have your timing chain replaced.
Check Engine Light is on
There are numerous reasons the engine light will turn on. One of which may be a timing chain problem. Your car's computer will show warning lights that need to be scanned and checked for trouble codes to determine the source of the problem. If the onboard computer detects something wrong with the emission system and engine operation, the check engine light will turn on. A stretched timing chain can contribute to poor engine performance and increased emissions that can trigger the check engine light and storing the diagnostic trouble code. Your mechanic will have to inspect the code and prescribe the repairs needed.
Engine rattles while idling
Every time you hear an unusual sound in your engine usually means that there is a problem. Under any normal conditions, the engine should always have a consistent and smooth sound, indicating that everything is functioning as it should. But if there is a timing chain problem, it can cause a vibration inside the engine, which produces a rattling noise as the engine idles. This usually means that the timing chain is loose and needs to be fixed immediately.
A vehicle's timing chain is an essential part of any engine. Without it, your car is useless. If a timing chain problem happens while driving, it could cause severe damage to your engine, and will likely cost you more once that happens. To prevent this and a large number of your expenses, it is best to immediately consult your local mechanic if you know of any of the timing chain warning signs we have indicated above.
What causes a bad timing chain?
Now that we have listed some of the timing chain symptoms, it is best to know what causes them. Knowing these three things will surely help you be more aware of your vehicle's timing chain.
A timing chain can either break with too much or not enough tension. If there is not enough tension in the chain, slack can grow, leading to a "slapping" of the chain. This will then result in early exhaustion for your engine. A chain with too much tension, when it is put under undue stress, may also lead to failure. When tension increases, chain friction and heat also increases, which can lead to a problem.
Engine seizures are caused by an engine overheating or running out of oil. This causes the pistons to also seize inside the cylinders. When a vehicle runs at high speed, and this happens, the sudden stop can break the timing chain.
Your vehicle's age and the number of miles it has driven is a significant factor for your timing chain to fail. The more miles you have on your car means that there is a higher chance that your timing chain is weak and will most likely break soon.
Nowadays, most automakers suggest having your vehicle's timing chain be checked and replaced every 60,000 miles.
When should you need a timing chain replacement?
Timing chain problems are common, especially for high-mileage vehicles. Like any other parts of the engine, a timing chain can still wear off in time and usage.
By now, you probably already have a better understanding of what causes a timing chain to break or to wear off. You probably also have a better grasp on the timing chain warning signs you need to be aware of.
Usually, when you notice any of these symptoms, it is best to immediately go to your local mechanic to have it checked and diagnosed. They are the best ones to give the appropriate repairs or handle the replacement.
While replacing a timing belt is expensive, the damage caused by timing chains is more costly to fix, so it is much better to tackle the problem early on. By taking it on before it could damage your engines more severely, you can save thousands of dollars of repair.
Replacing a timing chain is very complex and time-intensive. Getting it wrong could cause you and your vehicle more damage. When it breaks or worn out, the entire timing chain kit is replaced with new tensioners, guides, and other parts of the chain drive mechanism. Most mechanic and auto repair shops recommend replacing all of the chains in the car.
The timing chain cost for replacement may vary from $350 to $1500, depending on your vehicle's model, whether you need a timing chain for VE commodore or other models. We suggest getting a few quotes from auto repair shops around your area and compare them. Go with the ones at a fair price and have a good reputation, such as Machter Auto Parts. It is vital to get quality work done to save money in repairs in the future.
If you are planning to do the replacement by yourself, you will need to find the correct procedure to set the timing of the new timing chain once you install a new one. Replacing the timing chain is a big job, which will likely require multiple parts of the engine to be disassembled and rebuilt such as suction control valves, clutch slave cylinders, oil catch tank & oil pressure switch so it is not really advisable to do it on your own except if you have excellent knowledge in auto repairs.
But just so you have an idea what is done during a timing chain replacement, here is a quick run-down.
- Before anything else, the engine needs to be cleaned thoroughly with a degreaser.
- The mechanic will figure out the firing order of the car, which cylinder goes first, etc.
- Once that is ensured and figure out which cylinder Is first, the mechanic will remove the spark plug and place a screwdriver in the spark plug hole, with the piston near the top of the screwdriver.
- The battery cables will be disconnected and the radiator cap will be removed.
- The engine will be drained from all coolants.
- The mechanic will then remove the radiator hoses, all drive belts, the heater hoses, the water pump and fan, and the timing chain cover.
- There will be a mark on both the old chain and the tooth of the chain gear. The engine will be rotated until these marks are aligned.
- The mechanic will scratch a new reference mark across the chain and the gear with a screwdriver, before loosening the tension gear and removing the chain.
- All gears will be lubricated before the new chain is installed.
- The new timing chain will be placed onto the gears, making sure that the marks align properly.
- The camshaft sprocket bolts will be reinstalled. And punch out the old crankshaft seal.
- The new crankshaft seal will be tapped into the timing cover and the seal will be covered with oil.
- The mechanic will then start replacing the timing chain cover, reinstalling the fuel and water pumps and the fan.
- The radiator will be filled with coolant and the various belts and hoses will be reconnected.
- The battery will be reconnected and the engine will be started.
Also, to prevent untimely timing chain problems, you should maintain your engine properly and have your oil checked and changed as regularly as possible. Using premium quality engine oils and filters could help. Remember, unlike timing belts, timing chains are lubricated by the engine oil. And the lack of oil changes, low and poor quality can cause your vehicle's timing chain to break easily and wear off faster.
Keeping the proper oil level will also ensure that your timing chain is well lubricated. And a well-maintained engine, a timing chain can last longer than what it is expected to be.
Machter Auto Parts
However you plan on replacing your timing chain -on your own or by a professional, it is best to get the best timing chain kit from a very reputable source. Here at Machter Auto, we offer a range of alternators, starter motors, head gaskets that would perfectly fit your vehicle. As one of the very best replacement car parts providers in Australia, you can be guaranteed that all Machter car parts are the best in the market.
Check out the Machter Autoparts website online to shop for the best car parts online at the lowest price. You can also get in touch with one of our friendly experts to help you find the best car parts for your vehicle or if you need to buy wholesale car parts. Call the team at (02) 7801 4933.