A drive belt is an element of a belt drive that serves to transmit torque. The transmission of torque occurs due to friction forces or engagement forces (timing belts).
in VW vehicles Polo sedan a belt drive is used that transmits torque from the crankshaft pulley of the CFNA (CFNB) engine to the pump (coolant pump), bypass roller, tensioner pulley, alternator pulley and air conditioning compressor pulley.
If you do not change the belt on the polo in time, what will happen?
During its operation, the Volkswagen Polo Sedan drive belt is pulled out. This is provided by the manufacturer, in connection with which the mechanism drive belt tensioner pulley installed.
However, the tensioner roller also has a limited stroke, when it reaches the limiter, the belt begins to slip in the Volkswagen Polo drive mechanism, as a result of which it heats up. Overheating leads to a broken belt.
If in time (according to the prescribed regulations) the drive belt is not replaced by Volkswagen car Polo with CFNA (CFNB) 105 hp engine (85 hp) equipped with an air conditioning system, this will break the drive belt, resulting in the following consequences:
In the absence of a drive belt, torque is not transmitted to the pump, respectively, the pump does not work (coolant supply pump). The lack of forced circulation of the coolant leads to overheating of the Polo sedan engine.
- 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 the drive belt of the polo sedan breaks is the absence of forced circulation of the coolant, which quickly 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, the engines use a chain 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 only possible in polo sedan engines installed from November 2015. Read more about CWVA engines here.
Volkswagen Polo cars use several engines. When a 1.6 liter engine is installed on the Polo sedan, the timing chain changes on the drive. On engines with a volume of 1.4 liters, a belt is used. In order not to make a mistake in the drive, just look at engine compartment. In the case of a belt installed, a plastic casing will be placed on it, but if the drive is a chain, it will be protected by a metal case.
Manufacturer's official dates
It is necessary to timely replace the timing drive on a VW Polo car. If the belt breaks, the engine will be severely damaged and will need to be overhauled.
If a belt is installed
Under normal operating conditions, the drive changes as planned after 90 thousand km.
During this time, he uses his resource and becomes unusable. Particular attention should be paid to new spare parts, since the life of the engine depends on their quality. Polo sedan pretty popular car, so accessories are produced by many manufacturers.
It is advisable to make a choice in favor of original spare parts: this is guaranteed to save money on possible additional repairs.
The initial symptoms of a worn timing belt are:
- Slippage of the tension roller, followed by weakening of the belt tension;
- Overheating of the motor, which leads to boiling of antifreeze and frequent turning on of the fan to cool the coolant;
- A peculiar noise during the operation of the motor;
- Loss of power, engine stalls and does not start;
- The appearance of pops in the injector receiver and muffler;
- When inspecting the timing belt, cracks, wear of the profile track, and mechanical damage were found.
All such malfunctions indicate a shift in the valve timing and a weak drive tension. If at least one of the listed malfunctions is found, then you need to contact a service station to replace this important engine element.
Volkswagen Polo with timing belt
How many times to change the timing belt for a Volkswagen Polo also depends on what driving style, while how often it is used extreme driving. In such cases, it is necessary to change the timing belt as it wears out and the profiles abrade.
When replacing the timing drive, it is necessary to immediately change other related parts of this mechanism. In this case, it is recommended to use original products with the following article numbers for VW Polo with a CFNA 105 l engine.
Attention! Spare parts for Polo have a different cost, which depends on the manufacturer. In this case, it is recommended, despite the inflated price, to choose a trusted and well-known manufacturer, so that after replacement there is complete confidence in the reliability of the installed parts.
If a chain is installed
Since 2015, the Volkswagen Polo has rolled off the assembly line with a drive in the form of a chain instead of a belt. You can identify such an engine on VW Polo sedan cars by marking: CFNA - 105 hp. from.; CFNB - 95 l. from.
It would seem that a solution has been found for a reliable drive, because all segments of such an element are made of metal, and it is undoubtedly stronger than the material of the belt. But is it really so? How many times during engine operation do you need to replace the timing chain with a Volkswagen Polo? Why do some manufacturers recommend changing the chain every 60 thousand mileage or 3 years of operation, then every 30 thousand km or once every 2 years.
First, you need to consider the size of the engine. It is conventionally accepted on engines up to 1.4-1.6 liters to install a timing belt drive, and over 1.6 liters - a chain drive. The more powerful the motor, the greater the load on this element, and the more often the drive needs to be changed.
Secondly, on Volkswagen Polo cars, as a rule, a chain is installed on turbine engines, and a belt on simple atmospheric engines. At the same time, a hydraulic tensioner is used on engines with a turbine. Such a device automatically stabilizes the chain tension, that is, when this element rotates, the tensioner piston balances.
Attention! If the Polo has an engine with a timing chain drive, then the oil must be replaced every 8–10 thousand km.
Always clean oil in a turbine motor is necessary so that small particles of debris, sawdust, etc. do not get into the chain links. And the main reason is that debris does not get under the tensioner piston and it does not jam. Otherwise, if there is no balanced piston stroke, the chain drive will not work correctly and will quickly fail.
Volkswagen Polo with timing chain
Moreover, in Polo sedan engines with a turbine, the oil burns much faster than on conventional power units. Thus, in order to avoid the question of when to change the timing chain drive to the Polo sedan, experts recommend focusing on diagnostics no longer on mileage, but on sound. As soon as the drive tension is loosened, an increased characteristic noise from the engine will appear.
Vitaly. 7. 06. 2018. Motor Volkswagen Polo Sedan 1.6. equipped with timing chain. The metal chain must prevent breakage and guarantee a longer service life. But in fact, it quickly stretched out and needs to be replaced already by 70 thousand km. A backstop is needed in this drive, otherwise it works only due to oil pressure, which is created only after the engine is started.
Oleg. 8. 08. 2018. Good afternoon. I have a motor installed on my VW Polo car with a timing belt, not a chain. With this run of 80 thousand km. I recommend replacing it, for such a drive it is absolutely appropriate.
Vladimir. 9. 08. 2018. On the Volkswagen Polo with gasoline engines 3.2 and 3.6, manufacturers write that the chain can be changed after 150 thousand km. But for me, replacing the drive chain is a fairly common procedure, because it is single-row and stretches quickly. I recommend, if there is a choice, then buy a car with a two-row chain, and then you can forget about the timing drive.
Vadim. 4. 08. 2018. The mileage on the Volkswagen Polo was 8 thousand km. An interesting observation: more fuel is consumed along the highway than in the city. The chain on the sedan is supplied in two rows, the manufacturer guarantees its resource of 120 thousand km. While everything is fine, there are no significant comments.
Anatoly. 09/12/2018. The right wheel bearing was replaced for maintenance. After 65 thousand km. began to notice the clatter of the chain on the cold. I went to the service station for preventive repairs - they say it's time to change your timing chain. I had to make a replacement, although according to the regulations it was still possible to drive the same amount.
Sergei. 18. 09. 2018. My Polo has already traveled 150 thousand km on one timing belt. And all due to my inexperience, it turns out that according to the instructions it was necessary to change it at 90 thousand km. Don't repeat my mistakes. However, I want to say thanks to the producers. Yes, the belt rustled, vibrated, worn out, but it didn’t break!
Everything would be fine, the motor is like a motor, if it were not for the knock of the engine on a cold one. A lot of CFNA motors start knocking before reaching a hundred thousand kilometers, and in some cases a defect occurs already in the first 30 thousand.
Be careful when buying. A common problem is progressive knocking after a cold start.
Polo Sedan Engine - CFNA
At the time, the exit Russian market models Polo Sedan costing from 399 tr. (!) became a sensation and was considered an achievement of the Volkswagen concern. Still would! To get Volkswagen quality for that kind of money is a dream of many. But, as is often the case, low price badly affected the quality of the product - the engine of the Polo SedanCFNA 1.6L 105 HPwas not as reliable as expected.
CFNA 1.6 engine was installed not only on the Polo Sedan, but also on other models of the Volkswagen group, including those assembled abroad. From 2010 to 2015, this motor was installed on the following models:
- Volkswagen
- Polo Sedan
- Jetta
- Vento
- Lavida
- Skoda
- Rapid
- Fabia
- roomster
If you do not know which motor is installed on this particular car, then you can find out by its VIN code.
CFNA motor problems
The main problem of the engineCFNA 1.6 is an knock on cold. First, the knock of the pistons on the cylinder walls is manifested by a slight tinkling in the first minutes after a cold start. As the piston warms up, it expands, pressing against the cylinder walls, so the knock disappears until the next cold start.
At first, the owner may not attach any importance to this, but the knock progresses and soon even an inattentive car owner realizes that something is wrong with the engine. The very appearance of a knock (piston hitting the cylinder wall) indicates the beginning of the active phase of engine destruction. With the advent of summer, the knocking may recede, but with the first frost, CFNA will start knocking again.
Gradually, the CFNA engine knock "on cold" increases its duration, and one day, it remains even after the engine has warmed up.
Engine knock
The knock of the engine piston against the cylinder wall occurs when the pistons are shifted at top dead center. This becomes possible as a result of wear of the pistons and cylinder walls. The graphite coating on the skirts quickly wears down to the metal of the piston
In places where the piston rubs against the cylinder walls, significant wear occurs
Then the piston metal begins to hit the cylinder wall and then scuffs appear on the piston skirt.
And on the cylinder wall
Despite a large number of complaints, Volkswagen concern for years of release CFNA engine(2010-2015) never declared a revocable company. Instead of replacing the entire unit, the manufacturer performs piston group repair, and even then only in the case of a warranty claim.
The Volkswagen Group does not disclose the results of its research, but it follows from the sparse explanation that cause of defect, ostensibly, is in an unsuccessful piston design. In the event of a warranty claim, service centers replace the standard EM pistons with modified ET pistons, which supposedly should completely solve piston knock problem.
But as practice shows, overhaul of the CFNA engine is not the final solution to the problem and half of the owners again complain about the appearance of engine knock, after several thousand km. run. The other half of those faced with the knock of this engine, after a major overhaul, try to sell the car as soon as possible.
There is a version that chronic oil starvation caused by low oil pressure may be the true cause of the rapid wear of the CFNA engine. The oil pump does not provide sufficient pressure when the engine is running at revs. idle move, so the motor is regularly in oil starvation mode, which leads to its accelerated wear.
Resource
Declared by the manufacturer Polo Sedan engine resource is 200 thousand km, but traditionally atmospheric engines with a volume of 1.6 liters manufactured by Volkswagen must walk at least 300-400 thousand km.
Such a defect as the knock of pistons on a cold one makes these figures irrelevant. The Volkswagen group does not disclose official statistics, but judging by the activity on the forums, 5 out of 10 CFNA engines start knocking on runs from 30 to 100 thousand km. There are also known cases of manifestation of a defect on runs of less than 10 thousand km.
However, it should be noted that no cases of a stuck CFNA motor have been recorded. This is probably due to the fact that the knock progresses gradually and gives time to decide whether to repair the engine or sell the car.
Among the large number of complaints about knocking, there are isolated reports of successful long-term operation of the motor, which has a knock on a cold one, which allegedly does not progress and does not bother. Unfortunately, such reports are not confirmed by video recordings and, most likely, there is a knock not on pistons, but on hydraulic lifters. According to the reviews of car owners whose engine began to knock for real, it soon becomes impossible to ignore this knock. The ringing becomes such that “it’s a shame to stand next to the car” and “it can be heard from the balcony of the 7th floor.”
CFNA engine replacement
If the car is under warranty, the manufacturer performs a free warranty repair, replacing stock EM pistons with modified ET pistons. The cylinder block and crankshaft can also be replaced, but these expensive parts are not always changed under warranty.
Engine CFNA equipped timing chain drive, and the chain tensioner does not have a reverse lock. There are no grooves on the pistons either, so chain break/jump leads to Armageddon valve bend motor. The steel chain is designed to provide a higher resource and reliability in comparison with a belt drive. In fact, the timing chain of this engine stretches quite quickly and needs to be replaced already by 100 thousand kilometers.
The chain tensioner does not have a backstop and operates only due to oil pressure, which is pumped by the oil pump and occurs only after the engine is started. Thus, the chain tension occurs only when the engine is running, and while the engine is turned off, the stretched chain can move with the tensioner.
Due to this it is not recommended to park the car with the gear engaged, but without parking brake. When starting the engine, a stretched chain on the camshaft gears may jump. In this case, it is possible for the valves to meet the piston, which leads to costly engine repairs.
Over time, during operation, the standard CFNA exhaust manifold cracks and the car starts to growl in a bass voice. replacement exhaust manifold it is advisable to do it for free, before the end of the warranty, otherwise it will either have to be replaced (for 47 thousand rubles) or brewed (as in the photo), which will cost less.
Characteristics of the CFNA motor
Manufacturer: Volkswagen
Years of issue: October 2010 - November 2015
Engine CFNA 1.6 l. 105 HP belongs to the series EA 111. It was produced for 5 years, from October 2010 to November 2015, and then was discontinued and replaced by an engine CWVA from the new generation EA211.
Engine configuration
Inline, 4 cylinders
2 camshafts without phase shifters
4 valves/cylinder, hydraulic lifters
Timing drive: Chain
Cylinder block: Aluminum + Cast iron sleeves
Power: 105 HP(77 kW).
Torque 153 Nm
Compression ratio: 10.5
Bore/Stroke: 76.5/86.9
Aluminum pistons. Piston diameter, taking into account thermal gap for expansion, is 76.460 mm
In addition, there is a CFNB version, which is completely identical, but is equipped with a different firmware, thanks to which the engine power is reduced to 85 hp.
It is enough to drive to the Volkswagen Polo at least once in order to understand that it is not in vain that German-made cars have become the standard of quality and reliability. And the owners of these machines, especially those who have owned them for more than one year, know one more feature of them: incomparable maintainability. Almost any breakdown - whether it is a malfunction of the engine or any other system - can be repaired without much effort.
The exception to this rule is, perhaps, only one breakdown: a broken timing belt. And it’s not even about the element itself - it’s not at all difficult to replace it. It's just that this malfunction, which almost always happens while the car is moving, entails very serious engine damage.
VW Polo Timing Replacement: Preliminary Information
How does timing work?
The belt drive is used to synchronize the camshaft and crankshaft. The first is responsible for the timely opening / closing of the valves, the second - for the translational movements of the pistons according to the four cycles of the engine. It happens like this:
- At the initial stage, all valves are closed. The pistons are in their final position.
- At the moment of injection of the air-fuel mixture, the intake valves open - this is the first stroke.
- After they are closed, the fuel, under the influence of the pressure of the pistons, begins to shrink until it ignites from high pressure. This is the second beat.
- The gases formed as a result of the combustion of fuel push the piston back. Actually, this is the useful work of the engine. This movement of the piston through a number of mechanisms is converted into rotational movement of the wheels.
- And on the last, fourth, stroke, exhaust gases are ejected through the timely opened exhaust valves.
How well this mechanism works depends on Engine efficiency, that is, its power. With a slight desynchronization, the motor power drops significantly. And at a large one, when all its elements begin to work in antiphase, they simply collide with each other, deform or even break. As a result, the whole mechanism has to be changed.
Volkswagen Polo Timing Replacement
This operation, in terms of volume of work and its cost, is comparable to overhaul motor. To do this, car service masters will have to disassemble the Polo power unit literally by cogs, install new pistons, valves, and sometimes cylinders. Moreover: both the distribution and the crankshaft may need to be replaced. Not to mention the belt itself, because of which all this trouble happened. So the car will have to be left at the service station for a few days.
However, the replacement of the VW Polo timing belt is not limited to simply installing new components instead of failed ones. This mechanism requires careful tuning. In particular, the master will:
- polishing the valve plates so that they fit as tightly as possible to the cylinders and clog them tightly;
- adjusting the thermal gap of these elements so that the tightness of the combustion chambers is not violated when the engine warms up to its operating temperature;
- lapping of the pistons, which, on the one hand, must freely reciprocate inside the cylinders, but at the same time fit snugly against their walls so that the energy of fuel combustion is not wasted;
- in the process of assembling a new timing belt, carefully adjust it, thereby ensuring a clear synchronization of the operation of all its components.
It is clear that replacing the Polo timing requires a fairly large number of spare parts. Ideally, these should be branded parts. However, their cost is quite high, so you can use their analogues. Russian production, the quality of which is also very good. The main thing in this business is to make sure that all parts used for repair are of legal production. Firstly, this will guarantee their quality, and secondly, in the event of a factory defect (unfortunately, no one is completely insured against this), you could replace them under warranty.
Marginal notes: Single masters, having taken up the replacement of the timing, as a rule, offer car owners to purchase necessary spare parts. Thus, they relieve themselves of responsibility for their quality and durability. In our car service, almost all the components necessary for the repair of the Polo engine are always available, because we cooperate directly with their manufacturers. By the way, this also explains our low prices for them.
Replacing the timing belt Polo sedan
Is it possible to avoid such a complex and expensive repairs, how complete replacement Timing? Yes. And it's very easy to do it. It is only necessary to monitor the serviceability of the belt and in a timely manner, after warranty period work, replace it with a new one.
The manufacturer recommends reinstalling this element every 40-45 thousand km. car mileage. However, this figure is very conditional - the belt can easily work out its resource earlier. Therefore, its inspection is carried out by the master during each scheduled maintenance of the car.
This part is an elastic ring made of rubber and plastic with teeth on the inner surface that engage with the control gears of the shafts. For greater strength, a steel wire is laid between the layers of the belt, which, while increasing the reliability of this element, does not reduce its elasticity. If cracks, scuffs or damage to the edges are found on the belt, it is better not to risk it, but to replace it with a new one without delay.
Fortunately, replacing a timing belt on a Polo sedan is a fairly simple operation for an experienced craftsman. On Polo engines, access to the element is simple - for this you only need to remove the cylinder block cover and the belt cover itself.
Another thing is that during the installation process new part, the master will need to re-balance all other timing components and correctly set the tension level. If it is loosened, it can slip through the gears. And excessive tension is fraught with accelerated wear. For this, a special roller is provided, which is included in the standard set of parts required to replace the timing belt Volkswagen Polo sedan.
By entrusting the replacement of the VW Polo timing belt to specialists, you will not only save time, but you will also be sure that nothing threatens the engine of your car for thousands of kilometers.
On VW Polo cars, it is necessary to change the timing belt every 75-80 thousand km. It is recommended to check the belt every inspection for bending, fraying and stretching in order to avoid accidentally breaking the belt in the middle of the road.
The first symptom of a worn belt is a characteristic knock when the engine is running. Its unstable operation also affects (little power, stalls, poor reaction to the accelerator pedal). If the engine stalls and no longer starts, it is most likely the timing belt.
Instruments
- A set of wrenches.
- Set of heads.
- Ratchet.
- Screwdriver cross and flat.
- Hammer.
- Gloves.
The procedure for replacing the timing belt takes from 3 to 6 hours, depending on the level of training and availability necessary tools. It is recommended to carry out replacement at specialized service centers. Instruction:
- Place the car on a viewing hole or lifting box.
- Remove the engine protection.
- Disconnect the minus terminal from the battery.
- Remove the air intake.
- Disconnect the hose of the large branch of the ventilation system. It is located on the engine camshaft housing.
- Remove the non-return valve of the ventilation hose.
- Disconnect check valve and crankcase gas hose.
- Squeeze the fixing elements of the hose holder on the oil separator.
- Unscrew and remove the two bolts securing the oil separator to the cylinder head.
- Pull the pipe out of the hole.
- Remove the accessory drive belt.
- Remove refrigerant from the air conditioning system.
- Press on the locking elements of the block of the wire harness for turning off the air conditioning compressor.
- Disconnect the block after pressing the latch by pulling it towards you.
- Unscrew the bolts securing the flanges of the pipelines of high and low pressures to the air conditioner compressor housing. Dismantle pipelines. After removing them, you must immediately close the holes with plugs.
- Remove the three A/C compressor mounting bolts.
- Dismantle the air conditioning compressor of a VW Polo car.
- Unscrew and remove from the threaded holes the three mounting bolts of the compressor bracket to the engine block of the car engine.
- Remove the air conditioning compressor mounting bracket from the vehicle body.
- Drain the oil from the engine lubrication system.
- Remove the two bolts securing the flywheel or hydraulic transformer disc guard.
- Remove the flywheel shield itself from the car.
- Unscrew twenty bolts of fastenings of an oil crankcase of the car.
- Take out the oil pan. To do this, it is necessary to apply light blows with a hammer around the perimeter of the pallet.
- Unscrew the pulley mounting bolt, holding the engine crankshaft from scrolling. To do this, you need a mounting spatula.
- Dismantle the pulley.
- Drain the coolant from the engine cooling system of the vehicle.
- Unscrew and remove the three screws securing the coolant pump pulley.
- Remove the coolant pump pulley from the vehicle.
- Hang the power unit using a lifting mechanism.
- Disconnect the ground wire from the stud.
- Remove right suspension bracket power unit from the car.
- Remove the timing chain cover.
- Remove cover gasket.
- Mark the location of the timing chain, camshaft sprockets and sprocket crankshaft. This only needs to be done in case of re-installation. When replacing with a new belt, this procedure is not necessary.
- Press the timing chain tensioner and lock it in this position. To do this, you need to mount the pin.
- Unscrew the two bolts securing the belt chain tensioner and the timing gear.
- Remove tensioner from vehicle.
- Remove the timing chain tensioner shoe.
- Dismantle drive chain Timing from the car.
- Assess the condition of the timing belt.
- Replacing with a new timing belt and installing all parts is done in the reverse order of removal.
- Adjust the gas distribution phases (recommended in service centers).
- Check the vehicle's performance and the presence of extraneous sounds.
The procedure for replacing the timing belt is highly recommended to be entrusted to auto mechanics at service centers. Otherwise, if the belt is not installed correctly or if certain parts are not fastened correctly, this will provoke an even more in-depth and complex repair.
The importance of the timing belt on modern cars
Timing plays an integral role in the stable operation of the engine of any car. Malfunction or critical deterioration affects the entire car. He simply won't go. In the case of small engines (up to 1.4), a torn timing belt pulls out and bends the valve.