Home Brakes How to know when to change the timing chain. Replacing the timing chain yourself: is it realistic? What is the service life of the chains according to the maintenance regulations and the frequency of replacement

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How to know when to change the timing chain. Replacing the timing chain yourself: is it realistic? What is the service life of the chains according to the maintenance regulations and the frequency of replacement

The chain of the gas distribution mechanism of the engine - it is "endless", "no problem", "armor piercing" - there are thousands of epithets in its justification, and all of them are only positive. Of course, any car dealer will tell you - yes, there is a chain right there, so you can’t worry about replacement after 100 - 120,000 kilometers, you bought it, and what they say - forgot it! But is this really so, is it really not grindable, and in the end what resource does it have? Let's figure it out ...

Needless to say, a chain is definitely better than a belt, in terms of reliability it seems to have no competition. After all, all elements are made of metal and, as we know, it is much more reliable than rubber, plastic and fabric threads in a belt structure.

Why don't some manufacturers supply the chain?

Right now, the question seems to be hanging - why some manufacturers do not install them, but make belts? It's not practical, is it?

There are several answers:

This is noise. Whatever one may say, but even a perfectly tuned motor with a chain is still noisier than with a belt. Well, try to roll metal and rubber links on the asphalt yourself - you will understand what is noisier.

Design feature. The fact is that some engines, for the sake of silence, cannot use their "metal brother", because the belt drive is located outside the engine, that is, it rotates in the air. And so just taking and fixing the metal links will not work.
It is believed that the belt better grips the gears of the shafts, both camshaft and crankshaft. After all, the gear really has wide strips for engagement, but the chain has teeth, and even in oil! No, of course, they are also very effective in engaging the toe, and usually there are two rows of them. But as some manufacturers assure, they can jump over a tooth much faster than a belt.

Well, and actually the last one - tension. It is more difficult to tighten the chain mechanism than the belt. After all, the belt bends easily, and it is, again, in the air. But the opponent is inside in oil, and it is more difficult to pull it up - you cannot bend it properly!

Some write that it is also more difficult to change the chain mechanism, because you really need to disassemble almost half of the engine, but at the belt drive, I unscrewed the casing, removed and quickly put another one on! There is some truth in this, but in any case you will change the belt more often than the chain.

About engine maintenance

To begin with, I would like to say that the condition of the oil greatly affects the resource of the chain. It is inside, therefore, the better it is lubricated, the more the resource will grow. Also, indirectly, frequent replacement takes away from the engine any debris such as sand, dirt, etc., which breaks and wears out the chain mechanism, because sand can penetrate anywhere, including the connecting links. The new oil makes the pistons slide better, which relieves unnecessary stress on the chain mechanism.

In general, the result is this - in order to increase the resource, you just need to change the oil more often, at least by 1000 kilometers, but ahead of schedule. That is, the dealer claims 15,000 - change after 13 - 14,000, and ideally after 10,000, then the chain will last much longer.

Conventional engines

You know, I caught myself thinking that nowhere is there information about how long it takes to change the chain mechanism. That is, if you take a regular car with a conventional naturally aspirated engine (not a turbo - more about that below), the resource is often not limited by the manufacturer!

However, you can find information like this:

After a long mileage, about 150-200,000 kilometers, it is worth listening attentively to the operation of the engine, whether there is excessive beating and noise. If it manifests itself, you need to diagnose the circuit and, if necessary, change it.

That is, the main diagnostics for sound, and not after a certain mileage. Therefore, the resource differs from manufacturer to manufacturer, and from owner to owner.

However, if you knock out the numbers, it turns out:

Taking into account long maintenance (about 15,000 and more)

The chain serves about 150 - 170,000 kilometers.

Taking into account short maintenance (approximately 10-13000 km)

The chain can travel 300 to 350,000 kilometers.

If you take care of the car, then the chain mechanism is really the last thing you change! But wait, my friend changed in 15 - 20,000, what's the catch? YES, nothing, just your friend has an engine from VOLKSWAGEN, that is, a turbocharged, and even weak, volume of 1.2 - 1.4 liters.

Turbocharged engines

Quite different laws work here, turbocharged engines have much more torque and effort, respectively, more horsepower!

Therefore, it is not surprising that the chain mechanism has much less resource, the chain simply stretches here. Then it jumps to the tooth - the engine does not work normally - it consumes a lot of fuel, starts triplet, does not pull, or does not start at all.

Moreover, it manifests itself on weak engines, for example, such as 1.2 - 1.4 TSI. There was a constructive error, the width of the metal is dense - narrow.

Now think about the numbers with which VAG delighted the owners (albeit unofficially):

1.2 TSI engine - replacement after 30,000

1.4 TSI engine (122 HP) - 80,000

Engine 1.8 - 2.0 TSI - 120,000

That is, to call such races large - the language does not turn! However, just imagine how the timing belt would work in such conditions, in general, would it wear out after 10,000?

If we sum up the average figures for turbo engines:

The chain resource is about 120 - 150,000 kilometers. However, you need to read the maintenance regulations, some manufacturers have them strictly prescribed.

In the engines of the classic Zhiguli series VAZ 2101-2107, the gas distribution mechanism (timing) is driven by a double-row chain. The service life of the part is quite long and amounts to at least 100 thousand km of run. If symptoms of critical wear appear, it is advisable to replace the chain drive entirely, along with the gears. The procedure is time consuming, but simple, a skilled car enthusiast will cope with the task without any problems.

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.

Many Opel vehicles today use a timing chain drive. These include such popular models as Astra h and Astra J, Antara, Vectra, Zafira, Insignia, Korsa, Meriva. This drive demonstrates high reliability and durability. Its main advantage is the significant operational resource that the Opel timing chain has. A single-row timing chain lasts much longer than a rubber belt. However, it is also subject to wear and tear. Moreover, the consequences of its failure can be no less severe in comparison with the consequences of a belt break. Therefore, replacing the Opel chain is one of the most important service operations. To avoid serious and expensive repairs to the power unit, it is necessary to ensure its timely replacement, and only qualified mechanics should perform this work.

Why and when to replace the Opel timing chain

During operation, the timing chain is subjected to significant mechanical and thermal stress. As a result, it gradually wears out and sags. It is caused by wear on the joints and joints between the links. The result is backlash and sagging. In this state of the timing mechanism, the engine starts to operate in an unfavorable mode. Therefore, the Opel timing chain must be replaced urgently.
If the replacement is not carried out in time, then, due to the sagging, slippage and jumps on the sprocket begin by one or more teeth begin. This causes a violation of the valve timing, which in the most innocuous case can lead to the engine stalling and will not start without repair. In an unfavorable combination of circumstances, a meeting of pistons and valves can occur with all the ensuing consequences. In some cases, the chain breaks, which makes mutual pistons and valves almost inevitable. The result is not only bent valves, but also serious damage to the cylinder-piston group and the valve mechanism as a whole. To eliminate such breakdowns, a major overhaul of the motor is often required.
Given the above, it is important not to miss the time when the Opel chain of your model should be replaced. In many ways, it depends on the displacement of the power unit. For small engines (up to 2.2 liters), the average service life of a component is up to 150 thousand kilometers, on cars with engines larger than 2.2 liters, the service life is usually longer.
At the same time, experts recommend regularly checking the condition of the timing chain drive in a car service, at least every 50 thousand kilometers. This is because in many cases the chain can wear out prematurely. There are several main reasons for this. One of the main ones is problems in the lubrication system. With a low level or quality of oil, as well as with insufficient pressure, lubrication of the chain significantly deteriorates, which causes its very rapid wear. Also, the transportation of heavy loads, a sharp set of revolutions, frequent driving at high speeds, etc., negatively affects its service life.
The presence of chain stretching and the need to replace it may be indicated by an increased noise level from the timing area, which is heard during the operation of the power unit. In this case, computer diagnostics shows an error in the camshaft sensors. It should be noted that only a qualified specialist can determine the noise characteristic of this malfunction of the gas distribution mechanism. Therefore, it is necessary to pay attention to indirect symptoms. These include clanking sounds when starting the engine, unstable operation of the internal combustion engine, jerking, reduced throttle response of the power unit, rapid heating of the coolant, etc. The presence of such signs is a good reason to contact a car service to check the condition of the gas distribution mechanism drive.
When worn, the chain should only be replaced. This is a complex procedure that can take from 5-6 hours to several working days. Difficulty is also determined by the engine displacement. So it is easier to replace the chain of Korsa, Meriva, Astra with an internal combustion engine volume from 1.0 to 1.4 liters. Two chains are already installed on Zafira and Vectra, one of which is balancing, and the other is the main one. The Opel Antara uses two balancing chains and one main one, each of which is supplied with a tensioner, a damper and guides, which must also be changed. When carrying out replacement, it is imperative to use only original parts, including a repair kit. Thus, this procedure can be performed only in the conditions of modern professional service.

Fast and high-quality replacement of the Opel chain

If you need to replace the Opel timing chain, we recommend contacting our car service. We specialize in cars of this brand and have many years of experience with them.
We offer our clients the following benefits:
performance of work by highly qualified mechanics with extensive experience;
strict adherence to the technologies of the work carried out;
use of original parts that are offered by us at a favorable price;
attractive cost and tight deadlines.
Our specialists will be able to quickly, efficiently and at no extra cost determine the need for and replace chain drive units on Opel cars. At the same time, the car owner is guaranteed reliable and efficient engine operation for a long time.

Despite the growing popularity of timing belt-driven engines, timing-chain motors are still found today. Moreover, it can be seen on cars such as Mercedes, Honda, Nissan, Volkswagen, Audi and Skoda. The timing chain performs the same function as the belt - it drives the camshaft, which, in turn, opens and closes the valves in time. Some people think that this mechanism is designed for the entire service life. But this is not the case. In today's article, we will find out when to change the timing chain and how this procedure is performed.

About the resource

Many operating manuals do not indicate how long it takes to replace this element. But as practice shows, the drive resource is from 100 to 200 thousand kilometers.

Yes, the timing chain will be more reliable than the belt, and it does not break, but only stretches. But it is worth remembering that this stretch is compensated by the tensioner only up to a certain point. If the chain has lengthened, this is not a reason for an urgent replacement. But if you drive it for a long time, the valve timing may shift. After all, the tensioner will no longer be able to compensate for the length over which the element is stretched.

An interesting fact: the resource of chains on Honda engines (in particular, Civic) can reach up to 250 thousand kilometers. At the same time, no signs of replacement are observed.

Signs

First of all, you can find out about the upcoming replacement by means of computer diagnostics. So, during this operation, you can accurately determine the violation of the valve timing. Another indirect sign of stretching is increased fuel consumption. With a run, the chain can make an increased noise in operation. But it is worth remembering that these sounds can be short-lived. If there is only noise when starting the motor, this is normal. The oil pump simply did not have time to develop the required pressure.

Also note that if the chain has jumped, the motor will "walk" from side to side and run unstable at idle. These are the main signs, when they appear, it is worth inspecting the condition of the chain. However, experts advise not to bring the car to such a state. It is better to replace an element by mileage - every 150 thousand on average. It is also advisable to make a replacement when buying a used car. Not every owner will engage in such a business before the sale, since the chain does not emit special signs when partially stretched.

About buying

You need to understand that to perform such an operation as replacing the timing chain, you need not only this element. Also, with mileage, the shoes of the damper and tensioner wear out.

Therefore, it is worth purchasing items only in a set. This is the only way you can be sure that after replacement the chain will last a long time. As for the manufacturers, it is better to choose the original. Changing the timing chain on a Nissan (as well as on any other car) is not easy. And hardly anyone will like to disassemble the motor every 20 thousand kilometers. Therefore, you should purchase only high-quality original kits or a good analogue in the absence of the first option. If we talk about the price, this set for foreign cars will cost from 3 to 8 thousand rubles on average.

What else do you need?

Since we will be working with the timing mechanism, it is desirable to have a viewing hole. You should also prepare the following set of tools:

Socket heads.
Hexagons.
A piece of clean cloth.
Flat screwdriver.
Wooden block.
Torque and adjustable wrench.
Containers for draining process fluids.
Degreaser.
Sealant.

Getting Started

First of all, we need to remove the connected ignition cables to the coil. Then, using an open-end wrench, unscrew the coils themselves and put them aside. It is important to sign each of them so as not to confuse them during assembly (otherwise the car simply will not start). Next, we disconnect the air pipe from the valve cover. The latter is attached to the head with several bolts. The cover must also be removed. Next, we dismantle the right engine mount (not necessarily - depending on the design features of the car). After that, we prepare a container for draining the oil and unscrew the plug in the crankcase. We also dismantle the oil filter. After that we drain the coolant. If it is relatively new, it is important that the container is clean (the same goes for the oil). We put the container under the drain hole and open the tap.

When there are no more technical fluids in the system, remove the radiator and remove the alternator belt. Then we remove the clamp of the supply hose. At the next stage, we dismantle the block head. The cover is usually fixed with four bolts. You should also remove the oil pan. On some cars, you will first need to remove the intake exhaust pipe for this. Then loosen the water pump pulley bolts. This will remove the drive belts that go to the air conditioner and other attachments.

Next, we need to find a place between the crankshaft and the side of the engine crankcase. Here we place a wooden block and unscrew the shaft pulley. To do this, use a large size socket (usually 27 or 30).

Chain operations

So, we have freed access to the chain and now you can start dismantling it. To do this, remove the damper in the upper part, the bar that is responsible for tensioning the damper, and the hydraulic tensioner. After that, we take the lower bar and put it on the hairpin. Next, remove the old timing chain. Using a flat screwdriver, we get rid of the gear that is below.

Now you can compare the length of the old chain with the new one. It usually stretches by about 2-3 centimeters. This is a very serious indicator. How do I install a new circuit? It must be placed in place of the old one in the same way and additionally lubricated with engine oil. Then we remove all the dirt from the side of the engine by moistening a clean cloth in a degreaser. Also, it should be walked in those places where the sealant was previously found. It must be carefully scraped off and a new one applied.

Chain or belt?

The timing belt of cars, as we said earlier, can have two types of drive. This is a chain or belt. It is clear that if you have an engine with a timing chain, in no case should you put a belt. But what if you have to choose between two cars? There is no unequivocal answer to the question "which is better". Both drive elements have their own pros and cons. So, the chain is more reliable, since it never breaks and signals about the signs in advance. But at the same time it is noisy at work, and it is much more difficult to replace it than a belt. The latter, in turn, does not make noise at work.

But you have to change it more often - every 60 thousand kilometers. In the event of a break, bending of the valves is inevitable. The only exceptions are 8-valve engines. But they are practically not produced today.

Conclusion

So, we found out in what cases you need to change the timing chain and how to do it yourself. In total, the operation will take a full day of light. In order for the work to be done quickly, you need to prepare all new gaskets in advance, stock up on sealant and tools. Please note that if the block head is tightened incorrectly, the gasket may burn out and the cylinder head itself may be deformed. Tightening is done only

At the same time, the replacement of the chain is also a necessary operation in the case when the moment of its significant wear comes. In other words, the timing chain has a certain resource, at the end of which the element must be changed. During the operation of an engine with a timing chain, car owners and craftsmen tighten the worn chain in various ways. A fairly common solution is to increase the length on the working part of the chain tensioner, which is achieved using a steel tube of a suitable diameter. Some of them weld on the so-called "shoe" staples, etc.

It should be remembered that if the timing chain is stretched, then there is a high probability of incomplete coincidence of the valve timing. Such a defect significantly affects the operation of the entire internal combustion engine, the engine can run noisily, intermittently, not deliver full power, overspend fuel, start poorly, etc. A worn-out chain also significantly shortens the life of the "shoe" and quickly destroys the chain damper. In some cases, the timing chain may also be open, which leads to serious consequences for the engine. Next, we will look at how to change the timing chain itself, what is needed in order to change the timing chain and how much it costs.

Read in this article

How to replace the timing chain

To begin with, replacing the timing chain is standard procedure. In this case, the features of replacing the chain on a particular car model may differ. As a simple example, we will consider how to change the chain on a domestic VAZ 2106 for a better understanding of the features of this process. First of all, I would like to note that the correct replacement of the chain involves removing the front engine cover. However, many craftsmen, taking into account the certain complexity of this operation, prefer to rivet the timing chain links by weight.

We draw your attention to the fact that it is not recommended to use this replacement method unless absolutely necessary. In general terms, the links of the old chain are riveted, then a temporary connection is made to the new chain, after which it is rotated so that the new chain is on all sprockets. Further, the chain is pulled until the moment when "docking" with the previously riveted link of the old chain occurs, after which the link of the new chain is also riveted. The disadvantages of this method include the fact that the overall reliability of such a connection is questioned, the resource of the new circuit is reduced, etc.

In order to perform the replacement correctly, you need to remove the front cover of the internal combustion engine, as well as the pulley. Before starting work, it is also recommended to remove the terminal from, in parallel, the air filter housing and valve cover are removed.
Then the engine must be aligned according to the marks. The top mark is located on the inside of the sprocket, there is also a bump to the center of the camshaft housing. The lower mark is a strip on the crankshaft pulley, duplicated from the end of the pulley with a risk-tide. The indicated mark must be aligned with the mark on the front cover of the internal combustion engine. To make it more convenient, it is better to look at the alignment of the marks from the side where the distributor is located.
Next, you need to remove the ratchet holding the crankshaft pulley. To solve the problem, a wooden rail or a small block is placed on the mudguard on the left side, which will avoid impacts on the spar. Then a key is thrown onto the crankshaft ratchet, with which the internal combustion engine is scrolled. The specified key is a flat hex key with a long handle. This key is placed in such a position that it can have room to move and then hit the wooden block.
Now you can remove it from the ignition coil and put the gearbox in "neutral". Then the engine is cranked by the starter, the wrapped key at this moment beats against a wooden block on the spar. Usually the ratchet can be released after 2-3 rotations. We add that if there is no special key, then a knob with a head and a short shoulder will do. It should be taken into account that the head from the end must be held with the help of an additional tool, since the seating density may not be enough. Sometimes a spanner wrench, which has a small transition angle, is also suitable for solving the problem.
Next, the crankshaft pulley can be removed, loosen the bolts of the front cover of the power unit and then remove the cover itself. Further, the chain tensioner mounting bolts are released, after which the tensioner is removed. After removal, it is necessary to assess the condition of the "shoe" of the tensioner, inspect the element, check its development.
You also need to bend the lock washer of the upper sprocket bolt, after which the bolt itself is unscrewed, then the pulley is removed. A similar procedure is carried out with the auxiliary shaft pulley, which is also removed. For work, a 10 key is suitable, with which the chain stop is removed. The final stage is the removal of the timing chain itself.

It is worth paying attention to the fact that it is important to check the stars themselves. To do this, you need to take a new chain and put it on the sprocket, then grab the chain from below with your hand, squeezing it around the pulley. If the chain does not have a strong backlash when landing, then the sprocket is suitable for further operation.

Also, in a similar way, you can compare the degree of backlash when putting on a new and old chain. In the event that the backlash is the same, then you should think about replacing the pulleys with new ones. We add that replacing the sprockets is the recommended procedure when replacing the timing chain, regardless of their condition. If a car enthusiast is thinking about how much it costs to change the timing chain, then this nuance should also be taken into account in the list of additional costs.

Installing a new timing chain

During the reassembly process, a new chain is passed through the crankshaft sprocket, a pulley is inserted into the chain, after which the mounting bolt is baited. A camshaft star, tensioner and stop are also installed. Completion is considered to tighten the pulley bolt, bend the edge of the fixing washer on the sprocket bolt. Then the new timing chain is tensioned. Note that all the actions described above are carried out taking into account the fact that the engine did not spin, that is, the labels are set.
Now you can put the crankshaft pulley in place, install the front cover, and then tighten the ratchet. The crankshaft pulley is accurately positioned using the key orientation. You can hit the wrench to tighten the ratchet. Another method is to remove the flywheel guard, then fix the flywheel with a screwdriver or metal rod. Then the ratchet can be tightened.

As for the camshaft pulley mounting bolt, before final tightening, first check that all marks are aligned. To check, the crankshaft is rotated a couple of turns. In the event that the marks do not match, then the camshaft star is removed, after which the timing chain is moved forward or backward by one or two links, which depends on the degree of divergence when trying to match the marks.

Then the pulley is again installed on the camshaft to re-check the marks. When the marks coincide, the camshaft sprocket bolt is tightened completely, and then it is fixed by the fact that the lock washer is bent. At the end of all work, all the marks should be checked again, after which the valve cover is installed in its place.

Let's summarize

Given the above, we can conclude that replacing the timing chain is a responsible procedure. At the same time, the answer to the question of where to change the timing chain can be either a trip to a specialized car service, or performing all the actions in your garage.

It should also be borne in mind that when reassembling, it is extremely important to control the coincidence of the factory marks. Ignoring this rule often leads to the fact that a fairly common situation is when, after the owner has changed the timing chain, the car does not start or the engine works with obvious interruptions. In this case, re-disassembly is usually necessary, followed by correct labeling.

Finally, we note that the price of replacing the timing belt is somewhat different compared to replacing the timing chain. Changing the timing chain in the service is more expensive by 40-60% and more in comparison with a similar replacement of the belt drive on various models. If you do the replacement yourself, then you need to be prepared for the need to install a new chain, sprockets, tensioner and damper.