At the same time, the replacement of the chain is also a necessary operation in the event that 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 reduces 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 "joining" 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 chain 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 for movement and subsequent impact on a wooden block.
• Now you can remove from the ignition coil and put the gearbox in "neutral". Then the engine is cranked by the starter, the thrown-on key at this moment beats on a wooden block on the spar. Usually the ratchet can be released after 2-3 turns. We add that if there is no special key, then a knob with a head and a short shoulder will do. In this case, 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 box wrench is also suitable for solving the problem, which has a small transition angle.
• Next, the crankshaft pulley can be removed, loosen the bolts of the front cover of the power unit and then remove the cover itself. Next, 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 will 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. A key for 10 is suitable for work, 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 fastening 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, after which the ratchet is tightened. The crankshaft pulley is accurately positioned using the key orientation. You can hit the wrench to tighten the ratchet. Another way is to remove the flywheel guard, then fix the flywheel with a screwdriver or metal rod. Then the ratchet can be tightened.

With regard to 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, after which 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 sum up

In view of 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 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.

Read also

The machine will not start after replacing the timing belt, timing chain or other work on the timing mechanism drive. Main reasons, recommendations.

Despite the growing popularity of timing belt-driven engines, timing-chain motors are still found today. Moreover, it can be seen on such cars 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 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 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 250 thousand kilometers. However, there are no signs of replacement.

Signs

First of all, you can find out about the upcoming replacement by 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 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 will cost from 3 to 8 thousand rubles on average for foreign cars.

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, dismantle the right engine mount (optional - depending on the design features of the car). After that, we prepare the 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 screws. You should also remove the oil pan. On some cars, for this, you will first need to remove the intake exhaust pipe. 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.

Tags

Pay attention to the timing chain labels. The element must be installed so that the marks coincide on the pulleys and on the chain itself. After that, you can start assembling all attachments and components. Pay special attention to the block head.

It is tightened according to a special pattern, crosswise, observing the tightening torque. The exact moment is different for all cars, and this can be found in the owner's manual. In places where gaskets were installed, new ones must be installed. Old sealing elements cannot be used - they have already shrunk and will be ineffective.

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

How often have you thought about changing the chain on your bike? And in general, how do you know when it's time to change the chain? How to check chain wear? What's wrong with a worn out chain? Today we will try to give comprehensive answers to these questions!

Chain device

To understand what, how and why, you must first understand how the circuit works. Here is a photo of the usual " gaall chains"Or as it is now customary to call it" Roller chain»

1. Outer plate; 2. Inner plate; 3. Pin; 4. Bushing; 5. Roller.

Bicycle chains are missing item 4.

Where chain wear occurs

Contrary to popular belief the chain does not stretch over time... Wear is on the pins that connect the outer and inner link. The standard distance between two adjacent pins is 12.7mm. Over time, production appears on them and this distance increases. This increases the length of the chain, rather than stretching the outer and inner plates.

Why change a worn out chain

A worn chain adversely affects shifting and also causes faster wear on the rest of the transmission.

The wear of the sprockets is due to the fact that a new, unworn chain fits snugly on the sprocket, and the roller sits tightly on the pin of the chain. With the appearance of development, the pin begins to "roll" in the roller and "roll out" the distance between two adjacent teeth of the star. To understand this easier, just look at the schematic diagram below. The roller is green, the pin is black, and the star is orange:

Also, due to the gaps between the pin and the roller, dirt accumulates faster and more into the worn chain. And the dirt acts like an abrasive, further increasing chain and drivetrain wear and impairing shifting. Therefore, if you put the old chain on new stars, then it will kill them very quickly.

How to measure wear

Special wear gauge

There are many modern chain length meters from all sorts of famous brands. The essence of all meters is simple - measure the distance between several chain links and, thereby, determine whether it is worth changing the chain. The cost of such meters varies from 500 rubles to several thousand rubles.

We recommend the version with a caliper. It's simple, quick and for sure you or your relatives have a caliper of production from the times of the USSR lying around somewhere. Moreover, it is not difficult to buy it for little money at the nearest flea market. The accuracy of his measurements has hardly dropped since that time, and in the household it is a very useful thing.

The measurement technique with a caliper is simple. We take a vernier caliper, spread it 119mm and insert it into the chain links so as to measure the distance between them. If the caliper shows values \u200b\u200bfrom 120.6 to 120.9 mm, then the chain can already be changed. If the value is more than 120.9 mm, then in addition to the chain, you will have to change the stars with the cassette.

How often to change the chain

Often times the chain is not that expensive compared to the rest of the drivetrain. And in one set of transmission, you can change 2-3 chains. Therefore, in the long run, a circuit replaced in time will decently extend the life of other components. On average, manufacturers recommend changing the chain every 1500 km, but it all depends on your pedaling style, frequency and the quality of chain lubrication. Monitor the wear periodically and change the chain until it starts to wear out the transmission.

Outcome

It is not so difficult to monitor the condition of the chain, and the money saved in the future will more than offset both the time spent on measuring and the financial costs of a caliper. And if you also start using paraffin lubricants, about the test of which, then the savings will be enormous.

Welcome!
From time to time the chain of the "Gas Distribution Mechanism" wears out and, as a result, it requires replacement. It is also very pleasing that the timing chain can last a very long life, in contrast to the gas distribution mechanism belt. To be honest, there were even cases when the car passed about "180-200 thousand km" with the timing chain never changed, but it really was already very much stretched at that time and the guarantee that the chain would soon break was very high. And how many kilometers did you drive on only one timing chain?

Summary:

How much will it cost to replace the timing chain?
1) Replacing the timing chain, it will cost you around 250-500 rubles.

When do you need to change the timing chain?
The timing chain must be replaced when:

• Its tension, namely when the standard chain tensioner is no longer able to tension the chain.
• And also it needs to be changed when the car has covered about 80-100 thousand km. (Maybe more to go here, the most important thing is to look at its stretching, if the stretching of the chain is very large, then in this case it is better to replace it, otherwise it will simply break off)

What do you need to replace the timing chain?
1) Bricks.
2) Hammer.
3) Screwdrivers.
4) Wrenches.
5) A mounting paddle may be needed.
6) Hook, or whatever, what can hook the chain.
7) Wrench for unscrewing the crankshaft. (If not, then a 36 head will do!)

How to replace the timing chain on a VAZ 2101-VAZ 2107?

Withdrawal:
1) First, remove the head cover. (How to remove the head cover "", point "1-10")

2) Now turn the crankshaft until the mark on the camshaft sprocket meets the mark on the body.

Note!
The mark on the crankshaft should also match the mark on the camshaft cover!

4) Then turn on the fourth gear and put the car on the handbrake.

5) Next, loosen the camshaft sprocket mounting bolt.

6) Then remove the chain damper from the engine. (For how to remove the chain damper, read "in this article")

7) Then remove the chain tensioner shoe from the engine. (For how to remove the chain tensioner shoe, read "")

8) Next, bend the lock washer, which is located on the bolt of the accessory sprocket.

9) Now remove the bolt itself that secures the accessory sprocket.

10) Then remove the accessory sprocket.

Note!
After removing the sprocket, do not rotate the drive shaft, as this may damage the initial ignition setting! (see the photo at the very bottom of the article, under the heading "")

12) Next, completely unscrew the bolt that secures the camshaft sprocket.

13) Then, lifting the chain, remove the camshaft sprocket.

14) Then, deeply lowering the chain down, carefully removing it from all the sprockets.

Note!
To remove the timing chain, you do not need to remove the crankshaft sprocket!

15) After all the operations done, check if the mark of the crankshaft sprocket matches the mark on the cylinder block.

Note!
If the marks do not match, turn the crankshaft until they align!

Installation:
1) First put a new chain on the crankshaft sprocket.

2) Then put the chain on the sprocket of the auxiliary units.

4) Next, hook the chain.

5) And then lift the chain up to the place where the camshaft sprocket is installed.

6) Then put the chain on the camshaft sprocket, and only then reinstall the sprocket.

7) Next, check the coincidence of all the marks and tighten the timing chain. (How to check the coincidence of marks, see the article: "Installing the piston of the fourth cylinder at TDC - Top Dead Center") (And how to tension the chain, read "in this article")

Note!
If you do not understand how to tension the chain, then at the very bottom watch the video clip on the correct installation of the chain and on its tension!

8) Then tighten the camshaft sprocket bolt.

9) Then install the chain damper in place, in the reverse order of its removal.

10) Then reinstall the chain tensioner shoe again in the reverse order.

11) Next, replace the stop pin.

12) Now put into neutral and turn the crankshaft three turns in the direction of rotation.

13) Check that all the marks on the asterisks match.

Note!
If the marks do not match, install the circuit again and correct the situation!

14) If all the labels match then:
1. Tighten the chain tensioner cap nut.
2. Engage in gear.
3. Tighten all bolts on the sprockets.
4. Install all remaining parts in the reverse order of removal.

Important!
1) When working in a ditch, place bricks under the wheels of the car so that the car does not roll away!
2) If you are unable to remove the accessory sprocket, then try to move it with the mounting sprocket and then remove the sprocket!

For newbies!
Question: Where is the accessory drive roller located?
Answer:

Additional video clip:
If you do not understand how to install the chain on the car, then in this case, watch a small video clip in which everything is explained in detail with the engine removed from the car.

All modern cars are polysyllabic constructive installations, clearly calibrated to function in difficult, not single-line conditions. This topic is especially relevant to the power plant of the machine, which has a lot of components. Each of them is assigned a certain function, role. And the timing belt is one such element, damage to which can easily lead to serious damage and expensive repairs. Therefore, it is extremely important to know when to replace a failed element.

The most important part of the internal combustion engine

ATTENTION! Found a completely simple way to reduce fuel consumption! Don't believe me? An auto mechanic with 15 years of experience also did not believe until he tried it. And now he saves 35,000 rubles a year on gasoline!

The timing belt is the very part responsible for transferring the rotational motion from the crankshaft to the camshafts. The latter, in turn, control the distribution of the fuel-air mixture in the engine cylinders.

When the belt slips and is loosely tensioned, this leads to malfunctioning of the entire GRS mechanism. Proper camshaft rotation is not ensured, which results in poor timing control. As a result, the engine may malfunction, its power drop, increased fuel consumption or other problems.

Strong tension and breakage of the belt lead to large changes in the functioning of the GRS mechanism. For example, this can threaten a complex ICE repair, in which the cylinder valves open towards the piston, which accordingly leads to serious deformations of the engine internals. Major repairs or replacement of the motor are the only setup options in this case.

Preventing depressing consequences is the task of the car owner, who is responsible for the condition of his car. Nobody will do it for you. For this reason, it is extremely important to timely monitor the condition of the belt, because it can break for another reason. For example, it can be at the end of the service life. A belt is a rubber product with its own resource. When the time comes, it wears out for natural reasons, you just need to replace it on time, and that's it.

Components that function in tandem with the belt should also be diagnosed. For example, this applies to checking the rollers or the pump. If you ignore these parts, which ensure the correct tension and function of the belt in general, problems will not take long to appear.

In order to reduce the risk of damage to the internal combustion engine, it is recommended to check with the car dealer or dealer the timing belt resource periods. This is especially important when buying a car from the "secondary". If there is a service book for a new car, and you can trust it, then in the case of a used car, everything is much more complicated. For an uninformed person, there is practically no way to determine exactly when a part was replaced. You have to take your word for it, or take the car to a car service.

Belt: determination of replacement period

To understand when it's time to change a belt, you need to be able to take into account not one, but several factors. First of all, it is recommended to pay attention to the quality of the product. In other words, determine what kind of production it is. Today, in the conditions of availability of products, a varied number of products are supplied to the markets, including those from "left-wing" manufacturers. Even in stores, sellers often impose the purchase of not original, but universal products, supposedly no different from their relatives.

Of course, this is not the case, and you should not follow the lead of a dealer who is interested in selling his own product. It should be understood that spare parts of non-original quality are rarely of good quality and reliability. When operating a car with a non-original belt, the life-span is almost halved. It is worth changing only for a good product.

60-70 thousand km of vehicle mileage is the average belt indicator, its resource. If the car is used, then you should not blindly trust its former owner, waiting for the date to be replaced according to the passport.

Note. It is important to understand that on old cars the resource of a part is reduced much faster, as this is due to the wear and tear of the entire system, including machine components and mechanisms that are subject to natural aging.

Chain: some features and replacement timing

If the timing belt is a rubber band closed on both sides with notches (teeth), then the chain is already a metal part. Both elements perform the same function, ensuring the synchronous operation of both shafts. The difference between a chain and a belt is that the metal product has a longer service life.

The chain drive, in comparison with the rubber one, has both its advantages and disadvantages. With a longer history, the chain symbolizes the classic drive type. The use of a chain drive began in the automotive industry since the 50s of the last century, which coincides with the time of the transition to an ICE design with an upper camshaft.

If the chain were better than the belt, it would be used everywhere today. But as reality shows, on the contrary, most car manufacturers equip their cars with a rubber belt drive. The mere fact that the chain is noisy frightens off many.

The chain, unlike the belt, is made in the form of roller connectors, not teeth. Rollers are known to have less flexibility and make more noise when rotating.

A priori, more durable additional components function in tandem with the chain drive. For example, the tensioners of such a transmission must be inherently powerful in order to maintain constant tension on the metal chain. Compared to belt tensioners, the difference is huge. There is a large and heavy hydraulic tensioner, here is a light and miniature oil shock absorber. There may be several tensioners themselves, so you draw the appropriate conclusion not in favor of the chain.

We will not go into the topic of differences between a chain and a belt drive. Above, only a descriptive, comparative characteristic was presented. We are more interested in terms of replacement.

The classic answer from the seller of a car with a timing chain drive: I have a chain in my car, which, compared to the belt, is indestructible. Is it so? Of course, this is a misconception, but most consumers fall for the bait. The metal product, like the belt, breaks as a result, and this threatens the internal combustion engine with even greater problems.

Note. At one time, Mercedes was produced with a chain that could last a very long time. But the era of such cars is long over. Modern timing chain-driven machines are almost as vulnerable as belt-driven vehicles.

If the belt breaks, the internal combustion engine can be easily saved from overhaul by replacing the part with a new one in time. If the chain breaks, it threatens to be a complete failure. This is explained by the material of the product, which is much more massive than the belt. The metal chain severely damages the insides of the motor after a break, and only a few manage to reanimate the internal combustion engine after such cases.

So, the approximate resource of the chain is 200 or 250 thousand kilometers. Of course, compared to a belt, this is 4 times more, but do not forget that the passport data are given, which are valid only under ideal operating conditions. In most cases, the chain under Russian operating conditions does not withstand even half of the given period.

Another feature of the chain drive is also interesting. So, it functions well on some cars, the product's resource withstands almost the entire passport period, on other cars it does not last even 60 thousand km, like the belt. What does this mean? According to experts, about a birth defect. It is worth writing about this in more detail.

The problem is not always with the manufacturer of the metal chain or tensioner. Most of the chains break due to lack of lubrication. For example, this was observed on gasoline 1.6-liter Peugeot-Citroen internal combustion engines with Euro-4 standards or on 2-liter diesel units of Bavarian BMW car models.

Violation of the manufacturer's standards regarding lubricant quality, its abundance and replacement intervals greatly accelerates the chance of problems occurring. Almost any chain is secured with a roller tensioner. It is the latter that ensures the correct tension. In turn, the efficiency of the tensioner depends directly on the pressure of the lubricant. Again, here's an example: the Opel CDTI is powered by a 1.3-liter Fiat Multijet engine. With active driving in city conditions, a drop in the oil level is observed in such an engine. If the driver does not notice this in time, the pressure in the lubrication system will also decrease, and this will lead to a weakening of the tension.

Of course, it does not do without errors in the process of engineering elements. For example, chains and tensioners of power plants of the Volkswagen TSI concern for 1.2 and 1.4 liters, a vivid example of this.

No developer indicates the ideal exact time for replacing the chain. It is easier to determine the triggering of a chain by various indicators. For example, it can be a strong noise and phase shift of the HRM, which are determined using computer diagnostics. Experienced motorists will quickly identify the problem.

Note. On some motors, it is easy to analyze the consistency of the chain by a malfunction of the roller tensioner rod.

When purchasing a car with a timing chain drive, we recommend paying attention to the following points:

• As in the case of the belt, it is not appropriate to replace the product "just in case" here. If there is evidence of chain wear, in the car trade it will be possible to reduce the price of the car by several hundred or even thousands of dollars.
• We must be very careful about the issue of motor lubrication. It is imperative to check the quality of the oil used on the car. If it is of poor quality, then this is already a reason to think - is the chain in order?
• In addition, it is necessary to pay a separate question regarding the regular oil change. Lubrication should be carried out at least once every 15 thousand km of run.
• Be extremely attentive to all kinds of noises, knocks. It is especially important to pay attention to the noises that arise immediately after starting the internal combustion engine or during prolonged operation of the engine at idle. It is possible that these are the initial signs of a timing malfunction.

As a rule, the timing drive is located in the engine building in different ways. It is conventionally accepted to distinguish between front-wheel drive and rear-wheel drive arrangement. The first type implies such an arrangement of the drive when it is installed in the same plane as the belts of the attachment. The second type is when the drive is located in the same plane as the flywheel and gearbox.

The first-type exposure of the drive is more common, since it is easier to carry out according to the scheme. On the other hand, for several years in a row, automotive giants such as Audi and BMW have been using rear-wheel drive systems. Of course, such a solution significantly complicates the maintenance of the timing. It's good that the rear drive arrangement is used only on some models of these German cars, and even then, endowed with a chain, but not a belt.

At the end of the article, we provide useful tips that can help determine the wear of the timing belt and chain.

• Rough engine idling.
• Unusual noise of the unit during operation.
• Optimum permissible position of the tensioner, visible after removing the cover-protection.

About the belt:

• Unfavorable appearance of the product.
• Deviation from the set position of the tensioner roller and the shaft sprocket.
• Excessive temperature or defective roller bearing.
• Belt lengthening.