A drive belt is an element of a belt transmission that serves to transmit torque. The transmission of torque is carried out by frictional forces or meshing forces (toothed belts).

The VW Polo sedan uses a belt drive that transfers torque from the CFNA (CFNB) engine crankshaft pulley to the pump (coolant pump), idler roller, tensioner roller, alternator pulley and air conditioning compressor pulley.

If you don't change the polo belt in time, what happens?

During its operation, the drive belt of the Volkswagen Polo sedan is pulled out. This is provided by the manufacturer, and therefore a tensioner roller is installed in the drive belt mechanism.

Nevertheless, the course of the tensioner roller is also limited, when it reaches the limiter, the belt begins to slip in the drive mechanism of the Volkswagen Polo, as a result of which it heats up. Overheating leads to belt breakage.

If you do not replace the drive belt on a Volkswagen Polo with a CFNA (CFNB) 105 hp engine in time (according to the prescribed regulations). (85 hp) equipped with an air conditioning system, this will lead to a break in the drive belt, which leads to the following consequences:

In the absence of a drive belt, no torque is transmitted to the pump, respectively, the pump does not work (coolant pump). The lack of forced circulation of the coolant leads to overheating of the engine of the polo sedan.
- in the absence of a drive belt, torque is not transmitted to the polo sedan generator. Accordingly, the electrical part of the car will work for some time from the car battery, until it is completely discharged.
- in the absence of a drive belt, torque is not transmitted to the air conditioning compressor, but this is not the most critical in this situation.

Thus, the most dangerous thing when a polo sedan drive belt breaks is the lack of forced circulation of coolant, which quickly enough leads to overheating of the VW Polo sedan engine.

Replacing the timing belt polo sedan

Attention! On VW Polo sedan cars from 2010 to November 2015, engines with the letter designation CFNA (105 hp) and CFNB (95 hp) were installed. In these cars, a chain is used in the engine in the timing mechanism. Replacing the timing chain in the VW Polo sedan is not regulated by mileage and service life.

Replacing the timing belt is possible only in Polo sedan engines, installed from November 2015. Read more about CWVA engines here.

The manufacturer of Volkswagen Polo Sedan 1.6 has set a clear schedule for replacing the timing chain on this car - 80,000 km. But earlier wear of this consumable is quite possible. The reason for this may lie both in the driving style of the car enthusiast and in unfavorable driving conditions. The condition of the chain drive must be constantly diagnosed. This should be done after 25,000 km.

What is the threat of a worn chain?

Riding with a worn timing chain is fraught with serious consequences. Of course, the chain is not a belt, and it is unlikely to break, but with a certain degree of wear, it may well come off the sprockets. Then the pistons will collide with the valves, which will lead to deformation of the latter. The pistons and cylinders will also suffer, and the car will have to be overhauled. In addition, after a certain period of time, the chain will certainly stretch, and it will also have to be changed. In order not to forget when the chain was last replaced, you can put a plate under the hood with the corresponding inscription.

But what symptoms will indicate the wear of the chain drive:

• the car will no longer start immediately;
• when the engine is running, extraneous noise is heard;
• the car began to consume much more fuel;
• the motor power has decreased.

If one of these symptoms is found, you should turn your attention to the state of the chain transmission. Of course, there may be other reasons here, but nevertheless, chain wear is quite likely.

Repair of such complexity is within the power of every motorist. Of course, you can turn to specialists. But such repairs are not cheap. This is, firstly, and secondly, by changing the chain transmission personally, you get the experience that is so necessary for those who want to deal with their car.

If you decide that you will change the chain yourself, then stock up on everything you need. Go to the store and buy new supplies there. In addition to the chain itself, tensioners and dampers will most likely have to be replaced. Prepare the necessary tools for the repair:

• jack;
• spanners;
• set of heads;
• screwdrivers with different types of tips.

Now that everything is ready, you can proceed directly to the repair. Do not forget about safety precautions. Remember that doing this type of repair can be very easy to injure or even injure yourself, so be careful.

The process of replacing a chain drive without the involvement of specialists

As a rule, changing the chain drive takes 4-5 hours. Of course, everything here will depend on the level of training of the motorist. So let's get started.

1. We install the car on the overpass.
2. We remove the protection from the engine.
3. We de-energize the car by disconnecting the left terminal from the storage battery.
4. We remove the air intake.
5. Now pay attention to the camshaft cover. There is a ventilation hose on it. It needs to be removed.
6. We also remove the non-return ventilation valve.
7. The oil separator is bolted to the cylinder block with two bolts. We unscrew them and remove the oil separator. The branch pipe must be brought out through the hole.
8. Remove the accessory drive.
9. Now the refrigerant must be removed from the air conditioning system.
10. Pay attention to the clips of the air conditioner wiring harness block. You need to press on them and dismantle the block by slightly pulling it in your direction.
11. We remove high and low pressure pipelines. The holes formed in their place must be plugged immediately. Be sure to do this, otherwise dirt will enter the system.
12. We also remove the air conditioner compressor. To do this, you will have to unscrew 3 bolts.
13. We also remove the compressor bracket. It is also secured with three screws.
14. Now you need to drain the oil from the engine system.
15. Dismantle the flywheel shield.
16. Remove the oil sump. Here you will have to tinker, since you will have to unscrew as many as 20 bolts.
17. The oil pan will also have to be removed. He may not give in the first time. To remove it, you need to make uniform blows with a hammer around the entire perimeter.
18. Now we take a mounting blade and fix the crankshaft with it so that it does not rotate. We unscrew the bolt that secures the crankshaft pulley. Remove the pulley.
19. We drain the antifreeze.
20. Now we remove the pump pulley that supplies coolant to the system.
21. We take out the power unit using a lift.
22. Remove the suspension support bracket, which is located on the right.
23. Now remove the chain drive cover. Remember to remove the gasket. Assess her condition. It may also need to be replaced.

24. We mark the location of the chain drive, gears on the shafts.
25. Squeeze the chain tensioner and fix it in this position.
26. Remove the chain tensioners, having previously unscrewed all the necessary bolts.
27. We remove the shoe, and after it the chain itself.

Assembly procedures should be performed in reverse order. Be sure to check the operation of the engine. If uncharacteristic noises are heard, then something was done wrong, and the procedure will have to be repeated.

Video

Driving with a worn timing chain can have serious consequences. Unlike a belt, the chain cannot break, but it can jump off due to stretching. In this case, great damage will be done to the structure of the power plant. To restore performance, overhaul of the power unit will be required. To avoid unprofitable troubles, you need to change in a timely manner timing chain for Volkswagen Polo sedan 1.6.

Service intervals

According to the rules of the German automaker, the mechanism part does not need to be replaced during the entire service life, if it is in good working order. Installing a new circuit is only needed if it is faulty.

Unfortunately, the quality of roads and other negative factors cause problems even with the most eternal mechanisms. The drive component is stretched as a result of high loads, aggressive driving style, the use of low-quality components, etc. The consequences of working in such conditions are changes in the distance between the teeth, chain slip, timing disruption and engine breakdown.

Why chains are prematurely running out of a pledged resource

1. Due to design imperfections. The engines of the world's carmakers, and VAG in particular, are famous for their design flaws, leading to accelerated chain wear.
2. As a result of the use of fuels and lubricants of inadequate quality. Incorrect lubrication of the participants in the mechanism promotes accelerated abrasion of the contacting elements.
3. Due to frequent engine idling. Operation in a city with traffic jams is a frequent reason for the need to replace the timing chain.
4. Aggressive driving with cold engine. A sharp heavy load on the engine at subzero ambient temperatures is detrimental to the participants in the gas distribution mechanism.

Volkswagen Polo Sedan 1.6 CFNA and CFNB Circuit Malfunction Symptoms

The following symptoms will indicate the unsatisfactory condition of the spare part:

• Difficulty starting the internal combustion engine
• The appearance of extraneous noise, knocking, rattling when the engine is running
• Unreasonable excessive consumption of fuel
• Ignition misfires
• Deterioration of dynamics during acceleration
• Drop in engine power
• The light comes on, signaling an error in the operation of the internal combustion engine.

These signs may indicate other malfunctions of components of the automotive system. To determine the state of the circuit, you need to carry out computer diagnostics of the Volkswagen Polo engine. Late service calls increase the risk of costly replacement of the assembly.

Employees of Russian car dealerships recommend replacing the VW Polo sedan chain when the mileage reaches 80-90 thousand km. It is by this time that problems with the part begin to appear, phase displacement, which causes a drop in performance by 20-40 hp.

Timing chain advantages over belt

The chain drive, which the Volkswagen Polo sedan models popular in Russia have, has a number of advantages over the belt drive:

• Durability not prone to mechanical damage
• Wear resistance resource reaches 100 thousand kilometers or more
• Resistance to temperature changes, the chain does not change its characteristics either at low or at high temperatures
• Resistance to different types of loads, the chain does not break due to shock and vibration
• Resistant to local overloads.

Replacement parts

It is better to entrust the choice of components for servicing the gas distribution mechanism to a competent consultant. When replacing the timing chain of a German car with a 1.6-liter engine, a number of related spare parts are used: tensioner, dampers, oil seals, O-rings. For the convenience of car owners, there are kits for replacing the main chain, in which parts are assembled that correspond to a specific set of cars. It is not recommended to buy goods from third-party manufacturers and select positions based on the coincidence of external signs.

Genuine VAG components for the timing belt of the Volkswagen Polo 1.4TSI and 1.6MPI sedan have the following catalog numbers:

• 03C109507BA tensioner
• 03С109469 and 03С109509 dampers
• 038103085E crankshaft oil seal
• 03C109287G valve timing housing gasket.

The price of the set, taking into account the discount in the official online store of auto parts in Moscow AM-Parts, is 6900 rubles (as of November 2018). Branded parts are also used for engines of other Volkswagen models (Passat, Golf, Jetta, Sirocco, Turan), Skoda and Audi.

How to keep the circuit working

• Periodically check the condition of the circuit and related components
• Listen to the motor, especially when starting
• Follow the rules for servicing the oil system.

With proper operation, service and repair, the risk of breaking the timing chain is eliminated.

The AEV engine was installed on cars:

Volkswagen Polo 3 / Volkswagen Polo 3 (model code: 6N1) 1995 - 2000

the information is suitable for repairs and other cars.

So, after recently, hydraulic lifters began to knock, and even after warming up, and a verdict was made - for replacement. It's time to change the oil, along the way we will change consumables (oil and air filters), timing belt, poly-V-belt (it began to whistle like on basins) and oil as a finishing touch.

Before starting work, you must have:
1. A set of tools (heads, keys, hexagons, etc.)
2. Spare parts to be replaced (filters, hydraulic lifters, oil, belts)
3. Free time and space for repairs

Getting started

Remove the air filter cover, remove the filter and unscrew the 3 nuts that hold the lower part of the case

Remove the timing belt protective cover by unscrewing the clamps with a screwdriver, 2 in front and 1 in the back

Loosen the roller (in the direction of the arrow) and remove the V-ribbed belt

As you can see from the following pictures, the new one was bought for a reason, the new company Ae was installed in mid-November, therefore we conclude that the belts of this company are "not very" and we do not take them anymore

This was the reason for the unpleasant whistle. We will replace it with this

Go ahead, unscrew the crankshaft pulley. Here you need to be more careful with the bolts, because they have an internal hex which is easy to flare if they are loose due to dirt. Therefore, we thoroughly clean everything, you can spray a little HP. It is better to have spare, of course, in case of a breakdown. Along the way, we drain the oil by substituting a container for working off (marked with an arrow)

Use a spanner wrench to help rotate the crankshaft to unscrew the remaining bolts

Then we take out everything, including the timing roller and have the following picture

We go up
We remove the valve cover, and begin to unscrew the camshaft covers. The most important thing when reassembling is to position them correctly. Some of them (I have not all) have serial numbers (shown by an arrow), which indicate where they need to be placed, they also serve as a guide, i.e. they need to be exposed facing you, and not vice versa. It is also better to have a few studs on the M7 in stock, if you are not sure that the thread on them is good and nothing is ripped off (I had to replace 2, I need to tear something off the previous "masters" who screwed bolts into their heads instead of studs, and not on M7)

After we unscrew everything, we throw off the camshaft and here they are, the culprits of the repair

We pull out the old hydraulic lifters, you can use your hands, you can use a magnet and prepare a place for new ones

We unpack the new ones (by the way, the old ones were also INA?

While your partner was putting in the wetsuit, you can replace the oil filter in between. Lubricate the gum lightly with new oil and twist it by hand, that's enough!

True, some people force themselves and pull the filters with a knob, this is not necessary, nothing will flow from it, provided a good filter and sealing gum (installed KNECHT / MAHLE OC295). The installation location is marked with an arrow

After installing the hydraulic lifters, we assemble everything in the reverse order, observing the tightening torques! We pull the bolts of the camshaft covers with a torque of 10 Nm, the nuts on the studs 6 Nm + turn them 90 degrees.

Now, before putting on the timing belt, we expose marks on the camshaft and crankshafts. On the crankshaft gear, one tooth is cut down and there is a protrusion on the block that must be aligned (photo taken at an angle, so from this angle it seems that the marks are slightly not aligned)

There is a point on the camshaft pulley that needs to be aligned with the plastic tab on the guard (marked with an arrow)

After putting on the belt, we tighten the timing belt roller. Insert the hexagon by 6, pull in the direction of the green arrow, until a characteristic click, when the roller tongue will jump onto the mark (marked with a red arrow)

We assemble the elements of the air filter housing and, before closing the lid, we put a new filter (KNECHT / MAHLE LX568)

Now we are at the finish line, it remains to fill in a new oil. I pour the original from Nissan 5w-40, I get it through the drivers, who are prescribed oil from an authorized dealer for replacement on their official cars, but they sell it and pour some kind of cheap one, or don't change it at all, the car is not its own Experience of using this oil is very long , there were no problems with it, in winter it always started up the first time, even at -35 (and the winter was not particularly warm this time). Opponents of such a plan of oil, who are afraid for the oil seals, I want to say right away that nothing has squeezed out of me yet, and I think it is unlikely that this oil will squeeze out. Who might be interested, here is its article in the store KE90090042

P.S. a friend has been pouring this oil for 4-5 years, probably in AUDI 100 1985 onwards. and the engine runs like clockwork

Well, that's all, you can go wash your hands after renovation, comments are welcome, thank you all for your attention

Addition from seric:

When tensioning the timing belt, there should be no characteristic clicks, the roller is pulled in the other direction.

Install the tensioning roller and tighten the retaining nut by hand.
- The recess in the base plate -1- must grip the head of the fixing bolt -2-.
- Tension the toothed belt by turning the tensioning roller in the direction of the arrow until the arrow -3- is positioned over the slot in the base plate -arrow-.
- Tighten the clamping nut on the tensioning roller. Tightening torque: 20 Nm

After tightening the timing, it is necessary to turn the crankshaft twice in the direction of engine rotation until it stops again at TDC of the first cylinder.
After this, the position of the toothed belt and tensioner roller must be checked again.

Add-on from kentochek:

Replaced the video, took the original, because the difference in price relative to the same INA was only 200 rubles. Here is a photo of the new video

The installation process is the same as described above for removing the timing belt. The most important thing is to properly install the roller itself, you need the support plate to cover the bolt and properly tension the roller. You need to tighten it as described in the diagram above, and make sure that the signal tab does not "go" beyond the mark, so as not to overtighten the belt. The tightening torque of the nut that secures the roller itself, 20Nm

Decoding of the vehicle's original equipment (in English)
Decoding of VAG factory complete set in Russian!
Diagnostics Volkswagen, Audi, Skoda, Seat, error codes.

If you did not find information on your car, look at the cars built on the platform of your car.
With a high degree of probability, the information on repair and maintenance will be suitable for your car as well.

Volkswagen Polo sedans are equipped with power units of the EA111 family, the first developments of which began several decades ago. The CFNA motor was last upgraded in 2003. The engine received an aluminum cylinder block, at the same time the first models of power units with turbocharging and direct fuel injection appeared.

Under the BAG index, a 1.6-liter atmospheric power unit was installed on Polo cars. For the EA111 family, this motor was the first development. In terms of its design and technical characteristics, the engine is almost identical to the 1.4-liter TSI model.

Comparing both power units with CFNA and BAG indices, experts come to the conclusion that the units are related. Both motors are equipped with the same timing kits. The same chains are used on TSI engines ranging from 122 to 160 horsepower.

Since 2010, Polo sedan cars supplied to the Russian market have been equipped with CFNA engines. A similar power plant was received by the European versions of the popular budget car, as well as the Skoda Fabia demanded in the market. If necessary, such a motor can be found in disassembly both in Russia and in Eastern Europe.

In addition to CFNA, Volkswagen Polo cars were equipped with engines with the BTS index. The unit features a normally developed exhaust manifold, as well as a phase shifter on the intake camshaft. The engine was first installed on the Polo sedan in 2006. The BTS power unit is assembled on the basis of the power plant from the VW Golf 4, the package includes an aluminum cylinder block. The same engine can be found on Fabia, Toledo, Ibiza cars.

Exhaust manifold problems, configuration errors and mechanical defects

One of the pronounced shortcomings of the CFNA power plant is the poor design of the exhaust manifold. The exhaust ports are of different lengths and the catalyst is too close to them. As a result, the following difficulties are observed in the operation of the system:

• The exhaust gases from the first cylinder partially enter the second cylinder, which is in the purging stage;
• Similar processes, although to a lesser extent, are observed in the operation of the 4th and 3rd cylinders.
• Problems with the supply of fresh air to the engine are pronounced.
• Formation of a mixture, combustion of products is carried out with low efficiency, the fuel is not fully used.

In addition to the indicated drawbacks associated with design features, the CFNA motor has another drawback. In some cases, the exhaust manifold will crack between the 2nd and 3rd cylinders. The best option is to replace the collector, even with high-quality welding, the crack reappears after a while.

Problems with the crankcase ventilation membrane

For various models of gasoline-powered powertrains, problems with the VCG membrane are a standard situation. In CFNA engines, this element tends to crack over time. The consequences of such a defect are:

• The operation of the crankcase ventilation system is significantly disrupted.
• The traction characteristics of the motor are reduced.
• The current fuel consumption increases.
• The smell of exhaust gases can be felt inside the car.
• The oil filler plug is strongly sucked when the engine is running.

The purpose of the VKG membrane is to adjust the intensity of the removal of crankcase gases. In case of loss of tightness, formation of holes, this element must be replaced.

Timing chain breakage

The chain drive has been used on cars with engines of the EA111 family since the early 2000s. According to preliminary calculations, this solution should have reduced maintenance costs. As a result of the analysis of practical data, it was revealed that the costs in general have increased. Timing chain stretch is fixed at 100 thousand kilometers. After another 50 thousand, a rumble is clearly heard when starting the power unit and at the initial stage of work.

The engine has a hydraulic chain tensioner but no backstop. The chain tension is only possible when the engine is running, when the oil pressure reaches optimal values. When the engine is stopped, the spring and the remaining oil are responsible for the chain tension. As a result, the risks associated with chain slack in the absence of load, jump in start mode increase significantly. One of the fatal scenarios is the bending of the exhaust valves.

Wear and knocking of the piston group

One of the disadvantages of CFNA engines is the pronounced knock of the pistons when starting the unit and warming it up. Such defects can manifest themselves already at 15 thousand mileage, they are observed on 1 or 2 pistons. If the temperature of the coolant is less than 10 degrees, the knock is determined by the hard shift of the cold piston at an early injection advance angle set by the electronics.

The second reason for piston knocking is excessive pinching of the exhaust manifold. Due to the increased back pressure of the exhaust gases, the quality of the filling of the second cylinder decreases. Poor piston pin lubrication also results in a pronounced knocking sound.

The standard solution to the problem in dealerships has always been the replacement of pistons with new components. At the same time, the installation of improved models, in the name of which there is the letter ET, was considered the most effective. In parallel, the electronics unit was flashed. Since 2013, dealers have been replacing the exhaust manifold, but there is no information about changes in the firmware.

Many CFNA-powered car owners who have replaced the pistons on the ET have reported knocking after a while. First of all, such a defect is found on a cold engine, gradually becomes visible on a warmed-up power unit. The problem is associated with the development of pistons and walls, an increase in the working clearance. Moreover, such knocks do not lead to fatal consequences.

In order to minimize knocking, it is recommended to exclude the heating of the power unit after starting. It is also required to immediately turn on all systems that consume energy, which gives an additional load on the generator and motor. Another option is to install an exhaust manifold without a catalyst. This makes the outlet channels equal in length.

Publicly available statistics do not contain data on jamming of CFNA engines after the appearance of piston group knocks. More than half of the engines are working properly 200 thousand kilometers or more. Some cars have a mileage of 500 thousand km without replacing pistons and other work. In order to avoid sudden surprises associated with increased oil consumption, it is necessary to exclude operation on 92nd gasoline, especially low quality, and perform scheduled maintenance in a timely manner.

You can choose and buy a gasoline or diesel engine for various Volkswagen models.