Home Locks Bicycle repair: When to change the chain. When to change the timing chain for a Volkswagen Tiguan Replacing the timing chain when to change

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Bicycle repair: When to change the chain. When to change the timing chain for a Volkswagen Tiguan Replacing the timing chain when to change

The timing chain (timing) in the car is responsible for the normal operation of the engine. For novice drivers, this part is not the most popular, and few of them know exactly where it is located. Actually, they learn about it only after it breaks down. You can change the chain yourself, the main thing is to know exactly how the replacement is done.

Why change the timing chain

The timing chain functions when the vehicle engine is running. Over time, it undergoes wear and tear and breaks down. As an option, one of the chain teeth flies off, because of which it will begin to slip. Since the mechanism is located in such a way that it unites other moving parts in a rigid hitch, one slip will be enough to break the entire system. A break in the timing chain in many cars causes engine valve defects that will have to be replaced. On diesel engines, the camshaft may break, and as a result, it is necessary to replace not only the timing chain itself, but also the camshaft, valves and cylinder block gasket.

The process of changing the timing chain on some machine models takes up to 5 hours. Usually, not only the chain itself is changed, but also the tensioning mechanisms. It is not worth saving on details: a low-quality chain can break very quickly. Without fail, the timing chain on a car bought from the hands is changed, even if the previous owner assures that it is new.

How to determine system wear and when replacement is needed

During operation, the timing chain is in a bent position and constantly heats up. Operating under these conditions will cause stretching and sagging. This also affects the strength. Gradually, the chain begins to sag due to wear of the link joints, as a result, it begins to jump one or two teeth. The cause of faults and breakage is depreciation wear.

It is virtually impossible to visually identify the wear of the chain or by the sound it makes. In addition, it is also impossible to carry out such an examination with the naked eye. Therefore, when replacing a part, only its resource is taken into account. The service life depends on the power unit of the vehicle, operating conditions and mileage.

The manufacturer gives recommendations for changing the timing for each power unit. However, in practice, the actual life of the chain can vary significantly and vary depending on the conditions of use of the car. The manufacturer makes its recommendations based on tests carried out at the test site, and everyday driving in city mode destroys the part much faster. In addition, the replacement time may change depending on climatic conditions, which is typical for Russia.

The consequences of a breakdown of the timing mechanism for the engine

An open circuit or defects in the rollers lead to a loss of communication between the crankshaft and camshafts. The valves located in the cylinder head stop and freeze in the position in which they were at the time of the circuit break. In this case, the pistons function without interruption. Since the pistons and valves work in sync, the pistons will collide with the valves as a result of stopping. As a result, both parts are completely destroyed. Depending on the design of the engine, this problem is solved either by replacing the valve system and other parts with a piston group, or by installing a new motor.

Schedule and frequency of work

The timing chain, like any other part of the car, has its own working resource. Its duration is influenced by the operating conditions, the model and make of the car and the type of motor. On average, the life of the chain is 60 thousand kilometers or two years, but you should not delay too much with changing the part. There is no need to wait until it is worn out to such an extent that it starts to fall apart. Many modern vehicle models have integrated sensors that notify the driver when a given part is replaced.

The timing chain also has its own operating resource. After 100 thousand kilometers, it stretches and sags. The reason for this is the wear of the hinge joints and the increase in the distance between them. As a result, despite normal compression, tuned valves and serviceable ignition and power systems, the power unit is intermittently idling. The chain jumps one or two teeth. This can provoke either simply stopping the power unit, or jamming the valves and overhauling the motor.

How to understand if a part is stretched and is not working correctly

First, the correctness of the ignition is checked. If it is set incorrectly and each time after its readjustment it gets lost again, then this is the main symptom of an extended chain.

Choosing a chain mechanism: what kits are there

There are two main types of timing chains. Usually, when purchasing a new chain in car dealerships, they are interested in how many links it needs.

The first type is a chain with 114 links, installed on motors with a working volume of 1.2 or 1.3 liters. Domestic cars are equipped with similar chains.

The second type is a chain with 116 links. Install it on motors with a volume of 1.5, 1.6 and 1.7 liters. Such parts are used on domestic and foreign car brands.

How to replace a part

To change a damaged timing chain, you need to stock up on the following tools (for example, Toyota Avensis):

tension adjustment key;
key 15;
tension wrench;
large screwdriver or crowbar;
Retaining ring extraction tool.

How to remove

The timing case, which is attached with two bolts, is removed first. After that, the bolts securing the crankcase protection are unscrewed. They are unscrewed with keys No. 13 and 17. To gain full access to the timing drive, the engine protection is removed - this makes it easier to inspect.
After that, the mounting bolts of the compressor are unscrewed and the belt is removed from it.
The contacts are de-energized by removing the terminals located on the battery. It is advisable to put them in a rubber cover in order to guarantee safety during the repair. After that, the power steering fluid tank and the cooling system pipes are removed.
The compressor is locked in its original position. To correctly install a new timing chain, you need to pay attention to the special marks.
The bolts securing the generator are unscrewed and the terminal is removed. Simultaneously with it, the chip located on the right is removed. It is advisable to remove the generator itself - this is done only by unscrewing the lower bolt. This will allow easy access to the timing chain.
Wrench # 10 unscrew the bolts, remove the pump pulley.
Removing the timing chain protection is one of the most important steps. The bolts located at the top, bottom and center are removed in the order of their location.

How to put it on without problems

After removing the old timing chain, you must install a new one. They may differ externally - it all depends on the manufacturer.

Before changing the chain, it is advisable to fix the flywheel so that it will not move when installing a new part. For this, the starter is removed, and instead of it a special device is attached that fixes the flywheel in one position. Professionals do not resort to such a procedure - they simply unscrew the bolts at the bottom of the starter.

When adjusting the clutch, the transmission is locked at neutral speed. The clutch itself is turned 11 turns clockwise. Then, in place of the plug, a bolt is inserted that secures the crankshaft. In this case, the position of the flywheel is marked - the chain will be adjusted according to the mark.

The crankshaft itself is attached with two bolts, the pulley is held in one position with a special key.
The engine support is removed after the vehicle is jacked up and the 4 bolts have been removed, after which the support holder is removed.
If necessary, the crankshaft bolt is replaced with a new one.
New timing chain and rollers are installed only after removing the toothed pulley cover. Then a pin is installed, which will allow you to quickly and easily pull out the chain along with the rollers.
The tensioner is used only after a new timing chain has been installed. Worn out rollers are replaced with new ones.

After the crankshaft bolts are tightened, the location of the mark on the flywheel is checked. All removed parts are returned to their place in the order they were removed. At the end of the chain replacement, the operation of the vehicle is checked.

How to change the timing chain tensioner

The chain tensioner is used to tension the chain during operation. The design of this part is such that the tension is carried out automatically. Inside the tensioner there is a hydraulic pusher and a spring. Outdated models of such a part practically did not work, but recently they have been improved, becoming more reliable.

In order to change the chain tensioner, the following tools are required (for example, the replacement on the EP6 engine is taken):

Slotted screwdriver;
Key for 10;
Torx key for 30;
Key for eight, seven or a small ratchet;
Large ratchet and head for 27.

To access the chain tensioner from the engine, first remove the air filter and throttle assembly.

New tensioner installation process:

The air filter housing is unscrewed from the valve cover using a key # 10;
The air filter housing and guides are removable;
The ventilation branch pipe is disconnected from the valve cover;
Using the key # 8, the clamp of the inlet pipe is removed to the throttle assembly;
The throttle assembly is removed. Before that, it is advisable to remember its location;
The timing chain tensioner is unscrewed;
After removing the tensioner, you can measure the degree of chain elongation;
All removed parts are returned to their places in reverse order.

After changing and installing the chain, it is extremely rarely lubricated with engine oil, since it is lubricated during its operation inside the motor.

Installing a new part and the process of marking the chain of the mechanism on the video

Timely change of the timing chain is very important, since ignoring the recommendations of the manufacturer can cause damage to the power unit. Repair work on the motor will cost significantly more than repairing a single part. It is advisable to constantly monitor the condition of the timing chain, since its premature failure can be a consequence of the effects of climatic, road conditions and driving style.

During a cold start, the engine emits a suspicious metallic "growl" for several seconds? In 90% of cases, this is caused by a problem with the timing chain. It is necessary to check its condition and, if something is wrong, replace the component. If you do not carry out the replacement in time, you will have to spend a lot of money on repairs in the future.

What is a timing chain and is it subject to wear

One of the main elements of the engine gas distribution mechanism is a special belt, which ensures the well-coordinated operation of each component of this part of the car. Many machines use a chain instead of a belt. Thanks to it, the engine mechanisms rotate synchronously and function normally for a long time.

The chain runs whenever the engine is running. The load is high enough that the part gradually wears out and fails over time. Sometimes the chain just stretches. Sometimes a tooth flies off from it, which leads to slippage. Even the smallest damage will result in out-of-sync components and increase the risk of damage to engine valves. If the problem is not corrected in time, the camshaft may also break. It will be necessary to change both it and the cylinder block gasket, which is expensive.

How to understand what needs to be changed: the frequency according to the regulations

Many auto manufacturers say the chain is designed to last the entire life of the vehicle. Alas, this is only true when using the machine in ideal conditions. Longitudinal vibrations at high speeds cause excessive tension on the component and subsequent fracture.

Typically, this part needs to be replaced every 100,000 km. If there is a knock and a metallic rumble while driving, it means that the chain is stretched and slips. If such signs appear, replacement is required immediately! A decrease in engine power, a thick gray exhaust, loud noises in the muffler, a sudden increase in engine temperature for no apparent reason are also possible - it is by these signs, which most often appear not alone, but together, that one can easily determine the wear of an element.

Have you bought any used car? Be sure to inspect the chain, even if the owner says he recently changed it.

In some cars, in case of problems with the gas distribution mechanism, a special indicator lights up on the dashboard. If the chain is not replaced in a timely manner, it will jump and damage the block head. Further events depend on many factors. In the most favorable case, the valves are simply bent. In the worst case, their constituent elements are torn and the cylinder block becomes unusable.

How to choose the right spare part

Timing chains are single-row and double-row. Each option has its own advantages and disadvantages.

When installing a single-row version, the engine power increases slightly, the noise level decreases. The fact is that it is easier for the power unit to scroll one row of the chain than two.
The double-row chain leads to an increase in the noise level while driving, but it is much more reliable. Such a product is designed for a long service life.

Chains are subdivided into several types according to the number of links. The choice depends on the make of the car and the characteristics of the engine used in it. So, in VAZ 2101 and 2102 cars and other cars with an engine displacement of 1.2 and 1.3 liters, models with 114 links are used. A 116-link chain will come in handy for the owner of a car with an engine capacity of 1.5, 1.6 and 1.7 liters (these are VAZ 2103, 2107 and Niva). It is better to check the exact information on the suitable kit in the documentation for the vehicle.

DIY component replacement

Want to save money? The chain can be easily replaced with your own hands. However, this task is not an easy one, so it is better for a beginner not to take on it. Prepare to spend at least 3-4 hours. You also need to prepare a place and a set of tools in advance.

Consider the process of replacing the chain using the example of the Nissan Almera N16 Classic.

Platform and tools

It is advisable to carry out the work where there is a lift, overpass or pit. Prepare the following tools:

hex key 6;
socket heads in sizes 12, 13 and 14;
chisel and hammer;
a clean cloth to wipe off;
containers into which technical fluids will need to be drained;
adjustable and torque wrenches;
block of wood;
sealant and "anti-silicone" (degreaser);
and, of course, a new chain.

Many car enthusiasts like to arrange disputes among themselves about. To establish the truth, you need to know what advantages the chain has in the engine, the disadvantages of the chain, as well as what it is for and what design features the chain drive has.

Read in this article

Materiel

In a car engine, a metal chain is used in one unit: c. To understand its purpose, it is worth remembering the operation of the mechanism itself.

So, during the operation of the internal combustion engine for many, the fuel-air mixture enters the cylinders through. The combustion chamber is separate from the manifold. After combustion, the exhaust gases are removed through, which also separates the cylinder from the manifold. The valves are closed by the valve springs. And they open under the influence of cams.

The cams are located on the shaft axis in such a way as to open some valves while others are closed. The position of the cams relative to the valves changes when the camshaft rotates. In turn, it rotates through. Therefore, it is necessary to somehow transfer rotation from one shaft to another.

The circuit in the engine fulfills this function. The chain has been replaced on many makes and models of machines. It is quite rare to find a hybrid drive in which a chain and a belt are installed at the same time. In addition, the drive can additionally consist of several gears.

The chain drive on the gas distribution mechanism has been used for a long time and is not at all a relic of the past, as inexperienced motorists mistakenly believe. The solution is still used today by such giants of the automotive industry as BMW, Toyota, Mitsubishi and many others. This is due to the following advantages:

Strength. The chain rarely gets mechanical damage;
Wear resistance. With proper care, the timing chain resource is from 100 to 200 thousand kilometers;
The chain life is not affected by low or high temperatures;
The chain does not stretch under load (chain stretching occurs, but only over time, as the resource is depleted);
Resistance to local sudden overloads;

Disadvantages of the timing chain drive

Increased weight. In some cases, this point will seem controversial, and sometimes weight does matter. For example, in racing cars.
The complexity of the design, more technological and costly production. That is, the higher cost of the spare part for the end user. In addition, the design of the entire timing drive itself becomes more complicated, since a damper, a chain tensioner is needed. These parts also fail and often create additional problems.

Difficulty of replacement. In order to replace or at least check the circuit in the car engine, you will have to remove a special cover on, the cover of the block itself (depending on the make and model of the car).

Some motorists cannot or do not want to perform these operations on their own, as a result they are forced to spend additional money in car services. In addition, when replacing, it will be necessary to correctly set the position of the crankshaft and camshaft, which adds to the hassle.

Noise. Even a new chain will make more noise when the engine is running than a belt.

How to understand when it is time to change the chain in the engine

The timing chain, despite its durability, also has to be changed. Most often this happens due to the fact that it is stretched.

That is, its length increases by several millimeters. As a result, the tension deteriorates, the chain often jumps by 1-2 teeth of the gear. All this can lead to extremely negative consequences. For example, a seized engine.

The most alarming signal that will attract the attention of even an inexperienced driver is the characteristic noise emitted by a stretched chain: the rattling and rubbing sound of the chain. This is audible even considering the general noise during engine operation. In this case, it is even possible that the engine stalls, since the chain jumps by 1-2 teeth and the gas distribution is disrupted.

But, it goes without saying that it is better not to bring to such symptoms, but to regularly check the chain tension. You can also focus on the mileage. A chain for an engine of one type or another has a certain average resource (depending on the model and brand of the car). As a rule, this is an indicator of 100 thousand kilometers. To calm your conscience, you can check or replace the timing chain earlier. For example, after 60-80 thousand km.

Drive design at a glance

In order to independently change the chain and related elements, you need to know the structure of this part of the power unit. The mechanism that drives the camshaft of the VAZ 2106 engine includes the following parts:

a small drive sprocket is mounted on the crankshaft;
large idler gear;
the upper large gear is bolted to the end of the camshaft with a bolt;
double-row timing chain;
tensioner shoe, supported by a plunger rod;
damper - a metal plate with a wear-resistant pad;
chain runout pin is installed next to the lower sprocket.

In older versions of the "six", a mechanical tensioner plunger was installed, where the rod is extended under the influence of a spring. The updated modification of the car is equipped with a hydraulic plunger device.

During engine operation, the timing chain must be in a taut state, otherwise runout, accelerated wear and skipping of the links over the teeth of the gears will occur. A semicircular shoe is responsible for the tension, supporting the part on the left side.

After the camshaft sprocket (in the direction of rotation), a damper plate is installed, pressed against the chain drive. To prevent the element from jumping off the lower gear as a result of strong stretching, a limiter is installed next to it - a metal rod screwed into the cylinder block.

The drive mechanism is located at the front end of the engine and is closed by an aluminum cover, in which the front crankshaft oil seal is installed. The lower plane of the cover is adjacent to the oil pan - this feature must be taken into account when disassembling the unit.

Purpose and characteristics of the circuit

The timing drive mechanism of the VAZ 2106 motor solves 3 problems:

Rotates the camshaft, opening the intake and exhaust valves in the cylinder head.
It drives the oil pump by means of an intermediate sprocket.
Transmits rotation to the distributor shaft - distributor.

The length and number of links of the main drive element - the chain - depends on the type of power unit. On the "sixth" models of "Zhiguli", the manufacturer installed 3 types of engines with a working volume of 1.3, 1.5 and 1.6 liters. In the VAZ 21063 engine (1.3 l), the piston stroke length is 66 mm, on modifications 21061 (1.5 l) and 2106 (1.6 l) - 80 mm.

Accordingly, two sizes of chains are used on power units with different displacement:

1.3 liter engine (VAZ 21063) - 114 links;
motors 1.5-1.6 liters (VAZ 21061, 2106) - 116 links.

How to check the chain length at the time of purchase without recounting the links? Pull it out to its full length, placing both pieces close to each other. If both ends look the same, this is a 116 link part for long stroke engines (1.5-1.6L). On a short chain for a VAZ 21063, one extreme link will turn at a different angle.

Signs of critical wear on a part

During operation, the car is slowly stretched. Deformation of metal joints does not occur - the reason for the phenomenon lies in the abrasion of the hinges of each link, the formation of gaps and backlash. Within 1-2 bushings, the output is small, but multiply the gap by 116 and you will get a noticeable elongation of the element as a whole.

How to determine the malfunction and the degree of deterioration of the chain:

Once, in the process of diagnosing the "six" motor, I had to observe the following picture: the lengthened chain not only broke the damper, but also made a deep groove in the cylinder head housing. The defect partially affected the valve cover contact plane, but no cracks or leaks of engine oil were formed.

A chain stretched by 1 cm or more is capable of jumping 1-4 links along the gears. If the element "jumped" one section, the valve timing is violated - the motor vibrates strongly in all operating modes, significantly loses power and often stalls. A clear symptom is shots into the carburetor or exhaust pipe. Attempts to adjust the ignition and adjust the fuel supply are useless - the "shaking" of the engine does not stop.

When the chain moves 2-4 teeth, the power unit stalls and will no longer start. The worst-case scenario is a piston hitting the valve discs due to a large valve timing shift. Consequences - disassembly and expensive motor repair.

Video: determining the degree of wear of timing gears

Replacement instructions

To install a new chain drive, you need to purchase a set of spare parts and consumables:

double-row chain, suitable for a specific type of engine;
3 gears - two large and one small (sold as a set);
tensioner shoe;
damper plate;
power unit front cover gasket;
high temperature silicone sealant.

If, when diagnosing a problem, you find oil drips under the crankshaft pulley, you should purchase a new oil seal built into the front cover. The part is easy to change during the disassembly of the timing drive.

for a long period, while the chain was stretched, the teeth of the sprockets also had time to wear out;
for the same reason, the damper and tensioner linings were worn out;
the repair operation is very time consuming, it is impractical to repeat it because of each worn out drive element.

Tool and conditions of work

Of the special tools, you will need a 36 mm box wrench to unscrew the nut (ratchet) holding the crankshaft pulley. Since the ratchet is recessed, it is much more difficult to grip it with an open-end wrench.

The rest of the toolbox looks like this:

a set of open-end wrenches and sockets with a ratchet and a crank;
flat screwdrivers - regular and reinforced;
mounting blade;
pliers;
hammer;
rags, protective gloves.

It is most convenient to replace the timing chain on a viewing ditch in a garage. In an extreme case, an open area is suitable, but then you will have to lie down on the ground under the car to disassemble the unit.

Preliminary disassembly

The purpose of the preparatory stage is to provide easy access to the front cover of the power unit and the timing drive. What needs to be done:

Place the car on the inspection hole and turn on the handbrake. For ease of disassembly, allow the engine to cool down to 40-50 ° C.
Go down into the ditch and remove the sump guard. Immediately unscrew the 3 front bolts connecting the pallet to the end cover, loosen the nut on the bottom generator mounting.
Open the hood and remove the air filter box attached to the carburetor.
Disconnect the tubing over the valve cover. Disconnect the starter drive cable (in common people - suction) and accelerator thrust.
Dismantle the valve cover by unscrewing the fastening bolts with a 10 mm wrench.
Disconnect the electrical cooling fan connector.
Loosen and unscrew the 3 bolts holding the electric fan to the main radiator, pull the unit out of the opening.
Use a spanner wrench to unscrew the nut on the generator mounting bracket. Using a pry bar, slide the housing towards the engine, loosen and remove the drive belt.

In addition to the parts listed, you can remove other items such as the battery and main radiator. These steps are optional, but will help increase access to the chain mechanism.

Disassembly of the injector "six" is carried out in the same way, only together with the air filter housing it is necessary to dismantle the corrugated pipe leading to the throttle, the crankcase ventilation pipes and the adsorber.

Video: removing the electric fan and radiator VAZ 2106

Removing and installing a new chain

If this is your first time disassembling a camshaft chain drive, strictly adhere to the sequence of work:

Unscrew the ratchet nut with a 36 mm wrench. To loosen, fix the pulley in any convenient way - with a mounting spade, a powerful screwdriver, or a pipe wrench.
Remove the pulley from the crankshaft by prying from different sides with a flat screwdriver.
Remove the 9 front cover bolts using a 10mm wrench. Use a screwdriver to separate it from the mounting flange and set it aside.
Bend back the edges of the lock washers on the bolts of the two large sprockets. Grasping the flats on the end of the crankshaft with a wrench and keeping the mechanism from rotating, loosen these bolts with another 17 mm wrench.
Align the notch on the top gear with the lip on the camshaft bed.
Dismantle the damper and the tensioner plunger by unscrewing 2 each 10 mm wrench fixing screws.
Finally unscrew the bolts and remove both sprockets by carefully lowering the chain down.
Unscrew the stopper, remove the chain and small lower gear without losing the keys. Unscrew the tensioner shoe.

During the disassembly process, you may encounter a situation when the chain stretched over the norm has destroyed or cut the damper, and the debris fell into the crankcase. Ideally, they should be removed by dismantling the pallet. But since the oil pump is equipped with a screen, and waste always accumulates in the crankcase, the problem is not critical. There is almost no chance of residual parts interfering with the oil intake.

When replacing the chain on my father's "six" I managed to drop a piece of plastic damper into the crankcase. Attempts to retrieve through a narrow opening were unsuccessful, the debris remained in the pallet. Result: after the repair, my father drove more than 20 thousand km and changed the oil, the plastic is in the crankcase to this day.

Installation of new parts and assembly is carried out in the following order:

Clean the mating surfaces of the cover and cylinder block by covering the crankcase with a rag.
Lower the new chain into the cylinder head opening and secure with a pry bar to prevent it from falling.
Since you aligned all the marks before removing the chain, the keyway on the crankshaft should be opposite the mark on the block wall. Fit the small sprocket carefully and slide on the chain.
Install a new damper, stop pin, and tensioner shoe. Bolt the intermediate and upper gear with a chain.
Install the plunger and use the spring mechanism to tension the chain drive. Check the position of all marks.
Apply sealant to the cylinder block flange and screw on the cover with the gasket.

Further assembly is carried out in the reverse order. After attaching the pulley, it is recommended to re-check that the marks are in the correct position. The notch on the bead of the pulley should face the long strip on the front cover.

Video: how to properly change the chain on a VAZ 2101-07

Is it possible to shorten an extended chain

Theoretically, such an operation is quite possible - it is enough to knock out the cotter pin of one or more links and reconnect the chain. Why such repairs are very rarely practiced:

It is difficult to assess the degree of elongation of the element and the number of links removed.
There is a high probability that after the operation the marks will no longer be aligned by 5-10 mm.
The worn-out chain will definitely continue to stretch and will soon start rattling again.
The worn gear teeth will allow the links to jump easily when the chain is pulled out again.

Economic expediency plays an important role. A set of parts is not so expensive as to waste time and effort trying to repair the part by shortening it.

Replacing the timing chain drive will take an experienced craftsman approximately 2-3 hours. An ordinary car enthusiast will need twice as long without taking into account unforeseen breakdowns. Set aside a part of the day off for repairs and get the job done without rushing. Do not forget to match the marks before starting the engine and make sure that the mechanism is assembled correctly.