Oil seals symptoms of wear. Valve stem seals: wear, replacement location, types, photos, videos. Replacing valve stem seals without removing the head

Structurally in the engine internal combustion There are several types of seals that serve as seals for various movable joints, among which a special role is given to valve seals or, as they are also called, valve stem seals.

Purpose

Protection of the combustion chamber from oil ingress from the cylinder head.
Oil is supplied to the block head under pressure for lubrication camshafts, during rotation of which an oil mist is created in the cavity of the head, consisting of splashes of hot oil deposited on all elements of the head of the block.

Where are they?

Guide bushings for intake and exhaust valves are installed in the block head. A certain thermal gap is left between the sleeve and the valve stem, designed to expand the parts when heated.
In order to prevent oil from the block head from entering the combustion chamber through this gap on the bushings, oil seals are installed in the form of caps, for which they got their name - “valve seals”.

Device

The gland is a steel cylinder for a hard fit on the head of the guide bushing. On top of the cylinder, a layer of rubber or rubber (fluorine or acrylate rubber) is vulcanized in the form of a truncated cone to tightly wrap around the valve stem and remove oil during its working stroke. A spring ring is installed at the end of the cap for reliable contact of the cap with the valve body.

When do you need to change?

At work power plant, depending on the engine speed, every minute the valves perform about 200-1200 cycles, which negatively affects the life of the caps, causing their natural wear.
Car manufacturers do not give any data on the frequency of replacing valve seals and this work is carried out as signs of their malfunction are detected.

Symptoms of a malfunction:

Oil on the threads of candles, with severe wear of the caps, oil is already present on their electrodes;

Power drop, deterioration in dynamics and increase in fuel consumption;

Unstable start of a hot engine;

With an engine, it is the caps that are the first to suffer, as they are the most highly located in the engine, plus those in contact with the valves heated in the combustion chamber. In such cases, the seals simply "tan" and are no longer able to do their job, allowing the oil to freely enter the combustion chamber.

A seal failure can also be detected when the valve cover is opened to perform adjustment work or replace the gasket. This applies to engines where caps can be seen. The malfunction will be expressed in the absence of a spring, or an oil seal that has “removed” from the guide sleeve and “sits” on the valve stem.

How is the replacement process going?

On many engines, valve stem seals are replaced without removing the cylinder head, only partially disassembling it to get to the oil seals.

However, if the engine has been running for a long time with defective caps, then this definitely led to the formation of carbon deposits on the plates and valve seats, which must be removed for reliable engine operation.

In addition, in most cases, on the removed head, it is found that its plane is not parallel, which must be milled.

In any case, this work belongs to the category of complex and responsible and must be carried out in a car service, or in the garage of an experienced mechanic, where there are all conditions and essential tool to carry it out.

However, there is a nuance here. Replacement will only be advisable if the valve stem bushings are not worn. Otherwise, the service life of new parts will be extremely limited and repeated repairs will be required.

The fact is that if the valve stem runs in a guide with a large gap, then it will not move in the center of the sleeve, but with a warp and constantly press on one edge of the cap, causing its intense wear.

What happens if it's not repaired?

As follows from the theory, for the combustion of 1 liter of gasoline, 14-16 kg of air is needed, and such an air-fuel mixture will be most favorable for the operation of the engine, both in terms of fuel economy and full power output.

When oil appears in the composition of this mixture, this leads to its incomplete combustion, precarious work engine, loss of power and increased fuel consumption.

In addition, during the combustion of oil, carbon deposits form on the valve plates, piston crown and spark plug electrodes. With a strong flow of oil, when the caps are no longer able to hold it, misfires appear, or one of them stops working altogether.

Soot on the valves - one of the consequences of faulty caps

The deposit that appeared on the valve plates does not allow them to tightly "sit down" in the valve seats, which leads to a decrease in compression in the cylinders and interruptions in the operation of the power plant. Plus, a loose valve seat (especially exhaust valves) creates conditions for a breakthrough of hot gases from the combustion chamber and burnout of the valve disc.

If the above listed faults are found, it is recommended, without postponing for a saving tomorrow, to contact car service professionals to extend the engine life.

The internal combustion engine works as a single complex mechanism. Efficient interaction between gas distribution and crank mechanisms and from the engine lubrication system, oil scraper caps are largely provided. The driver must not only be familiar with the function of the parts, but also correctly diagnose wear and the need to replace oil seals.

What are oil seals for?

The movement of the piston in the cylinder is facilitated by the splashing of oil under the skirt. But a thin film of lubricant is removed by oil scraper rings, which are dressed on the piston. On the other hand, in the gas distribution mechanism, the contact surfaces are lubricated.

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A kind of oil suspension is created under the head cover of the block. On the border of the cylinder and the cavity above it, the valve stem seals are located. Their task is to prevent oil mist and oil from the valve stem from entering the combustion chamber of the cylinder.

It is not difficult to guess, given the constant contact with the valves of the gas distribution mechanism, that the caps are under constant load. Each valve makes hundreds of movements per minute, and the oil is heated to high temperatures.

How many and where are they on the engine

Based on the purpose and work being done, it is easy to determine where the valve stem seals are located. If we consider the engine assembly, then the cap is dressed on the valve stem. Structurally, the part is a plastic part in the form of a sleeve made of a special stable material and a metal base.

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The location of the valve stem seals in the engine during its disassembly is determined as the cylinder head, at the point where the valves enter the working chamber.

If the engine has 8 valves and 16 valves

Puzzle over how many valve stem seals in 16 valve engine, do not have to. The number of these critical parts is exactly equal to the number of valves. Those. if in an engine with 4 cylinders it is indicated that there are 2 valves per cylinder, then there will be 8 caps. In more modern motors, where there are 4 valves per cylinder, the number of seals will be 16. Provided that the engine is 4-cylinder.

Reasons for wear

Along with the constant mechanical impact, the cap is exposed to the aggressive action of heated oil and impurities in it. Do not forget about hot exhaust gases at the onset of the exhaust stroke.

Over time, natural rubber roughens, the walls of the sleeve crack and wear out. Although the regulation Maintenance did not determine the exact interval for replacing the caps, if the corresponding symptoms appear, it is not worth delaying with the replacement with new parts.

How to determine if a replacement is needed

Among the main criteria that directly indicate the need to replace valve stem seals are:

Oiling the spark plug electrodes. Oil has the ability to seep into the combustion chamber.

Increased oil consumption. Compared to the traditional "appetite" of 1 liter/10,000 km, the same consumption increases to a liter for every thousand.

The appearance of blue smoke at the exhaust. Part of the oil has time to burn out during the compression stroke.

Sometimes there is a dilemma, what is the cause of the blue smoke from exhaust pipe. By mistake, wear of parts of the cylinder-piston group is often called such a reason. To finally decide whether you need an overhaul of the engine or replacement of valve stem seals, it is enough to check the compression. The normal value of this indicator allows you to confidently point to the caps.

By the way, for a short time the problem increased consumption oil will allow you to remove the use of special tools. A special softening additive for valve stem seals will restore the functionality of parts for a couple of thousand kilometers. The additive is effective after 500-700 km of run after addition. Do not delay the repair, most likely similar symptoms of engine wear will appear again soon.

How to find everything you need for work

When contacting service center Changing valve stem seals is not difficult. However, this approach will mean for the owner of the car the option of performing work with the removal of the head of the block, which involves replacing the gasket and mounting bolts. And yes, it's a big time investment. This option means a significant overpayment.

Most simple option is to do the work yourself. To do this, it is worth preparing a tool for replacing valve stem seals and buying a set of consumables for one engine.

Which caps are suitable: sizes and price

When determining which valve stem seals are best for a particular motor, you should pay attention to the original kit. You will receive a quality product, and the price does not seem significant.

For example, a set of original spare parts for popular models costs from 1.3 thousand rubles. (Toyota Camry 2.4 l) up to 2.2 thousand rubles. (BMW X3 2.5 L). When compared with available analogues, changing valve stem seals is cheaper by an amount of 800 to 1200 rubles, respectively.

When choosing analogues, do not be too lazy to check the compliance of the details according to VIN number, or ask the store manager for advice.

We select a puller

To successfully replace valve stem seals without removing the head, you will need to buy a special tool. As a last resort, you can borrow such a set from a neighbor in the garage.

To do the job, you will need a tool, better known as a cracker. When choosing, you should pay attention to the equipment indicating its suitability for use with a particular engine. The use of universal devices is also allowed. However, some station wagons are still designed for a certain type of engine - with an HV or SOHS layout.

The tool is designed to clamp valve springs by mechanical pressure. After removing the crackers, access to the valve stem seals opens.

Do-it-yourself removal and installation procedure

At the initial stage of the work, the car is de-energized, the ignition coil is turned off and the candles are unscrewed. The piston of the first cylinder is set to top dead center. Next, to change the valve stem seals, perform the following operations:

Remove the valve cover and all hoses. The rocker bolts are loosened.

We remove the rockers. At the same time, make sure that crackers do not scatter when removing from the axle. Do not remove the rocker arms from the axle and do not turn them over so that oil does not leak from the hydraulic compensator.

Install the puller and compress the spring. As a result, two crackers are released that need to be removed (it is convenient to use tweezers).

We remove the valve plate, we get access to the valve spring and washer.

We press out the installed part. It is possible to use either an impact collet or pliers to tighten the cap along the axis.

Before installing a new cap, check the play of the valve itself in the guide. If the indicator does not exceed 0.15-0.20 mm, install the valve back.

A new cap is put on the lubricated valve shaft using a mandrel. The spring and valve disc, crackers are returned in reverse order.

Use a torque wrench when tightening the rocker bolts. Often the tightening torque is set at 50Nm.

If it is necessary to change the valve stem seals in cylinders 2 and 3, the pistons must also be moved to the end position.

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Every driver passenger car with an internal combustion engine must be able to distinguish signs of wear of valve stem seals, since otherwise the development and hardening of valve seals is fraught with a number of consequences. If the problem is identified in time, then without any problems you can buy a puller for cracking and replace rubber-metal parts even without removing the head.

How valve seals work

Valve stem seals, as they are called in the common people, are installed directly on the valve stems, they are a combination of a rubber cage and a steel sleeve, designed to increase the rigidity of the structure. When the valve opens, the cap covers it, preventing oil from flowing into the cylinder. Of course, a certain part of the lubricant still gets under the seal, but this is the norm - there is a natural lubrication of the assembly. Over time, the elasticity of the part decreases, it shrinks, and there is an increase in the volume of leaking liquid. As a result, the oil "leaves", forcing you to top up to the norm more and more often.

Signs of wear on valve stem seals: how much oil the 1.8 engine takes

The first and foremost symptom of hardened, worn valve seals is overuse. engine oil. True, for some engines, the regulations allow noticeable deviations from the generally accepted norm of 200-300 ml per 1000 kilometers. So, 1.8 turbocharged engines installed on models of the Volkswagen AG auto concern (Volkswagen, Audi, Skoda, Seat) legally require topping up with lubricant up to 500-700 ml for every thousand kilometers. A similar situation develops around PSA Peugeot Citroën engines developed jointly with BMW (also installed on Mini models) - passport data speaks of a “norm” of 1000 ml of engine oil, which must be topped up in the engine every 1000 km.

Things like this highlight the importance of knowing "your" oil consumption. If the power unit between service operations consumes significantly more than the recommended values, then this is a serious reason to think about replacing the valve stem seals.

The second sign of oil leaving the cylinders due to the loss of their condition by the caps is bluish-gray smoke from the exhaust pipe, which can be clearly seen in the first minutes of engine operation and then when shifting gears, while pressing the accelerator pedal. Also eloquent evidence of the above problem is oil deposits on the threaded part of the spark plug. When the pressure in the combustion chamber rises, the mixture supersaturated with oil is partially squeezed out through microscopic gaps. For example, through the thread of a candle, where the gap is no more than 0.3 mm. Under the influence of high temperature, gasoline from the mixture evaporates, leaving behind a fair "reserve" lubricant. Indirectly indicates the death of the caps and dark soot on the electrodes.

Exactly the same soot appears on the cylinder walls. And if you ignore the problem, then one day, due to plaque, the valve will simply burn.

Video tips for checking for oil fat

How to understand that you need to replace the caps, and not the engine piston system

It is very easy to confuse signs of drying out of valve seals and the development of a cylinder-piston group. In both cases, the problem matures after 200,000 km, often occurs on used cars that were bought without proper diagnostics. Moreover, zhor oil, blue smoke are characteristic of both diseases. That's just hardened valve stem seals do not affect the compression rate, which usually drops with wear piston rings, the walls of the pistons and cylinders themselves. If the car consumes too much oil (from 1 liter per 1000 km), but the compression in the cylinders is normal, then 90 out of 100 are caps.

An additional check is carried out on a running engine with an unscrewed oil filler cap: an engine requiring CPG repair should have smoke from the neck, while worn caps do not cause this.

The price of a cracker puller Toyota, Volkswagen, Audi and the principle of its operation

An integral attribute of replacing valve stem seals on any engine, be it a Lexus or a VAZ, is the so-called cracker. Is it branded or universal (suitable for motors various brands) a tool for clamping valve springs, without which it is not possible to carry out repairs. The principle of operation of the cracker remover is quite simple: the cracker is attached to the engine body with reference points, with the help of mechanical pressure on the plate, the valve return spring is clamped, which allows you to dismantle the crackers.

It should also be noted that universal pullers are often not so multi-tasking - some designs are suitable for motors with an ONV, ONC, HV layout, others are designed specifically for servicing Opel SOHC engines, etc. You should clarify this point before buying an instrument.

Dryer price:

• for overhead valve engines - from 3500 rubles;
• for OHV, OHC, CHV engines - from 2000 rubles;
• a comprehensive set of tools for cracking down on engines of Toyota Camry, Volkswagen Golf, Mitsubishi Lancer, etc. - 20,000 rubles.

A cracker, as in the photo, is an essential attribute of replacing valve stem seals on any engine

Change without removing the head: the cost of a repair kit Ford, Mazda, Nissan

In the official service, experts usually insist on the option of replacing caps, which involves removing the cylinder head. So it is much easier to dismantle / install oil seals, and everything spent on fuss with Cylinder head time is paid by the client. Thus, a decent amount of money accumulates. But if you do not reach the removal of the “head”, then you will need less nerves, time, you will not have to spend money on laying cylinder head and new bolts. When accessing a cracker (it is not necessary to buy - you can, for example, temporarily borrow from a friend), the matter remains small. It is necessary to purchase a set of branded or non-original valve stem seals.

The cost of the original repair kit (valve seals):

• Toyota Camry 2.4 - 1300 rubles;
• Ford Focus 1.8 - 1500 rubles;
• Volkswagen Golf 1.6 - 1800 rubles;
• Nissan Qashqai 2.0 - 1500 rubles;
• BMW X3 2.5i - 2200 rubles;
• Mazda 6 1.8 - 1600 rubles.

Replacing MSC with Mitsubishi Lancer IX 1.6

Consider the step-by-step process of replacing valve seals with Mitsubishi Lancer 1.6 ninth generation without removing the cylinder head.

• The ignition coils are dismantled, after which the candles are unscrewed.
• After unscrewing the six bolts, the valve cover is removed
  The hoses are disconnected.
• To prevent the hydraulic lifters from falling out, they can be fixed with wire or plastic clamps.
• It is necessary to unscrew 13 bolts securing the rocker arm axles. The axles are removed as an assembly without turning over (to avoid oil leakage from the compensators).
• So that the crackers do not fall into the pan, the engine holes are clogged with foam rubber, clean rags.
• Using marks on the pulley and head, TDC is set in the first and fourth cylinders.

• The biscuit remover is attached with one part to the valve head body, the second part rests against the plate, which allows you to release and remove the biscuits with tweezers.
• After removing the plate with the spring, access to the cap appears.
• The dismantling of the cap itself should ideally be done using a special removable device. But in the absence of such, you can adapt to work with pliers. However, in the absence of delicacy, it is easy to damage the valve guide.
• Before swapping the old and new caps, it does not hurt to check the valve itself for play.
• The new cap, lubricated with oil, is pressed with a suitable mandrel - you can use a 10 mm wrench.
• The spring and plate are returned to their place, with the help of tweezers and a puller, crackers are put back.
• The replacement of the MSC in the remaining two cylinders is carried out after turning the pulley along the marks and setting the TDC.
• It is highly desirable to tighten the rocker axle bolts with a torque wrench in compliance with the values ​​recommended by the automaker (50 Nm).

Features of replacing caps on a 16-valve VAZ Priora

To gain access to the caps on the Prior, you will first have to unscrew the candles from the wells, dismantle the ignition coils, and also remove the throttle assembly. After that, it will be possible to unscrew the valve cover bolts in order to remove the rocker arms and actually replace the MSC with a puller. In general, the layout is the same as in the case of Lancer: TDC is set in the cylinders, crackers and springs are removed, new seals are installed, and reassembly is in progress. As a rule, the whole complex of works takes from the performer from 8 to 12 hours.

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Quite often you have to notice that increased smoke appears from the exhaust pipe of a car. Sometimes situations reach the point that the car is literally shrouded in clouds of thick smoke. It is quite obvious that for every motorist the appearance of excessive smoke indicates the appearance of certain problems with.

We note right away that not always, but often increased smoke indicates serious. At the same time, it will not be difficult for experienced drivers to determine the cause by the color and composition of the exhaust. However, for beginners, it is not always easy to understand why the engine smokes, as well as to establish the cause and identify rings or caps. Let's figure it out.

Read in this article

White or black smoke from the exhaust pipe

Let's start with the main types of smoke for a better understanding of the problem. So, white smoke from the exhaust pipe is quite normal for cold engine warm-up modes. Moreover, it is a mistake to believe that it is smoke. It's actually steam. Vaporized water is a natural product of the motor.

In a cold exhaust system, this vapor partially condenses and becomes visible, and water usually appears at the end of the exhaust pipe. As the engine warms up, condensation decreases.

The colder the environment, the denser the steam. At temperatures below 10 ° C, steam is also formed on a well-heated engine, and in frost at minus 20 - 25 degrees it acquires a thick white color with a bluish tint. Humidity also affects the color and saturation of steam. The larger it is, the thicker the steam.

Note that if steam is visible in the warm season, it is quite possible that this is due to. Its shade depends on the composition of the coolant, the weather, the illumination, and also on the amount of coolant in the combustion chamber. Sometimes it can take on a bluish tint, resembling "oily" smoke. But, unlike oil smoke, which leaves a bluish haze in the air for a long time, the vapor quickly dissipates.

It is quite difficult for an inexperienced motorist to appearance determine what is the source of the smoke. In this case, you can use a proven verification method. To do this, on a well-heated engine, briefly close the cut of the exhaust pipe with a sheet of white paper, while the condensed vapor in the form of water droplets will gradually evaporate when it hits the paper and will not leave obvious greasy marks.

If this simple test confirmed that exhaust system it is steam that comes out, not oil smoke, it is necessary to take measures to eliminate the malfunction that contributes to the penetration of coolant into the cylinders.

Most often, fluid can enter the cylinders through insufficient broaching (in winter period often there is leakage of coolant at the junction of the block and the head), burnout and less often as a result of the formation. By opening the radiator cap or, it is easy to identify the smell exhaust gases and a film of oil on the surface of the coolant.

All problems associated with white smoke from the exhaust pipe require the elimination of not only direct causes, but also a mandatory check of systems that can affect their appearance: the switch on sensor, the clutch or the fan itself, the condition of the radiator, its plugs, hoses or connections. If white smoke and its accompanying defects are noticed, then the car cannot be operated, as the defects progress rapidly.

• We go further. Black smoke from the exhaust pipe indicates a re-enrichment of the fuel-air mixture or a deterioration in the combustion conditions of the fuel. Therefore, we are talking about malfunctions. Such smoke is usually clearly visible against a light background and represents soot particles - products of incomplete combustion of fuel.

Black smoke is accompanied by high fuel consumption, often poor starting, precarious work engine, high toxicity of exhaust gases, and often loss of power due to a non-optimal composition of the air-fuel mixture.

It is important to understand that monitoring the symptoms and quickly identifying the problem will further reduce the cost of repairs and avoid serious and rapidly progressing engine breakdowns.

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Why are piston rings stuck? The main signs for self-identification of a malfunction, diagnostics. Do-it-yourself piston ring decoking.

Use of anti-wear, anti-smoke and other additives to reduce oil consumption. Pros and cons after applying the additive to the engine.

Oil seals, or, as they are also called - valve seals / valve seals, primarily prevent excess oil from entering the engine. Just like most engine parts, they are made of special rubber and wear out over time and work less efficiently: they separate and allow excess oil to pass through. And this, in turn, leads to an increase in oil consumption. Today we will try to understand not only what valve stem seals are, but also the causes and first signs of their wear.

What are oil seals.

Oil seals are essential in engines to prevent oil and debris from entering the combustion chambers. They are often called valve seals, and this name fully reflects the role they perform.

Valve stem seals are located directly on the valve stems, and consist of three main parts:

• Base;
• Actually cap;
• Spring.

The base is a sleeve made of steel. It plays the role of the frame of this part and gives it the necessary strength. The cap itself is the main element of the part. It is made from a special rubber resistant to high temperatures and friction forces. The cap is mounted inside the sleeve, and when mounted on the valve, fits snugly around the stem and removes oil. And the spring is mounted in a special annular recess of the cap and ensures its tightest fit to the stem.

As for the oil that these caps must remove, it is supplied to the gas distribution mechanism by an oil pump. It is designed to lubricate timing parts that experience friction and increase their resource. At the same time, its penetration into the cylinders through the valve groups is highly undesirable, since, when burned, it forms carbon deposits that accumulate on their walls.

It should be noted that in modern engines Internal combustion valve stem seals have to function in rather harsh conditions of high temperatures and increased mechanical loads. In addition, they are also negatively affected by the substances contained in the removed lubricating fluid. Therefore, manufacturers of valve stem seals use the most durable materials that are resistant to friction, thermal and chemical effects for their manufacture.

The location of the oil scraper caps in the engine

The head with camshafts and valves is mounted on the cylinder block. The valve stem moves through the guide bush. The thermal gap between the leg and the sleeve is closed with caps. The oil seal is positioned so that oil from the head does not enter the combustion chamber. The camshaft journals receive oil under pressure, and the rest of the nodes - due to splashing. Remove the engine head and camshafts, you can see the location of the glands in the valve seats.

Wear of valve stem seals

Like any other part of an internal combustion engine, regularly experiencing a whole combination of negative effects of various kinds, valve stem seals gradually but steadily wear out. Their most loaded rubber part loses elasticity over time, cracks appear in it. In addition, over time and under the influence of high temperatures, the clamping force of the spring inevitably weakens. As a result, the wear of the valve stem seals leads to the fact that the oil is not removed from the valve stems and it enters the chamber combustion engine.

As practice shows, the resource of valve stem seals installed in modern internal combustion engines is approximately 100,000 kilometers. After the car has passed this distance, they must be replaced. Experts also recommend changing valve stem seals in car engines that have been out of service for a long time.

In addition, it often happens that valve stem seals wear out prematurely for one reason or another. In such cases, they, of course, also require replacement with new ones. The fact that the time for this kind of engine repair has come is evidenced by several characteristic signs.

signs of wear

Significantly increased oil consumption; The following signs may indicate wear on the valve stem seals:

• The appearance of soot on the electrodes of spark plugs;
• The appearance of blue exhaust gases at the time of engine warm-up.

The increase in the "oil appetite" of the engine when the valve stem seals are worn is quite logical and understandable. The point is that that lubricating fluid, which is not removed by them from the valve stems, enters the cylinders and burns out. Accordingly, it is irretrievably lost from the lubrication system of the power unit, and the oil has to be topped up more often than usual.

As the oil burns, the blue-colored combustion products come out, coloring the exhaust gases in the corresponding color. When the engine warms up, the oil burns almost completely, so the blue smoke disappears.

In addition, if oil, not removed by caps, enters the cylinders, then its smallest drops also settle on the electrodes of the spark plugs. Accordingly, after combustion, carbon deposits form on them.

Consequences of wear of valve stem seals

As soon as the listed signs of wear of the valve stem seals begin to appear, you should check the gas distribution system of the car, and special attention should be paid to the valve stem seals. Experienced motorists do it on their own, less sophisticated ones go to a service station, where experienced specialists perform diagnostics.

It should be noted that it is strongly not recommended to operate the engine with worn valve stem seals. As practice shows, if you ignore this defect and do not eliminate it, then it is almost inevitable:

• The power of the power unit will decrease;
• On the Idling it will start to stall periodically;
• Turnovers will "float";
• Compression will drop significantly;
• Carbon deposits will appear on cylinders, pistons and valve seats.

As for soot, its appearance is indeed a very serious "bell", since its formation may well lead to a very expensive overhaul power unit.

HOW TO REPLACE OIL SEALS WITHOUT REMOVING THE CYLINDER HEAD

If the problem with the wear of the valve stem seals was detected in time by the driver, he can replace them without removing the cylinder head. In a situation where the solution to the problem has been delayed, it will be necessary to dismantle the parts in order to remove carbon deposits from the pistons and valves. Depending on the car model and engine, the process for replacing valve stem seals will vary. But there are several main steps that are common to all cars: Before you start replacing the valve stem seals, you need to let the car engine cool down completely; Next, the cover of the gas distribution mechanism is removed; Marks are made on the crankshaft and camshafts, after which the drive is loosened and the camshaft is removed;

The pushing valve springs are dismantled - they are “dry out”; Using pliers or a collet, it is necessary to remove the worn valve stem seal from the valve stem; Lubricate the valve stem and the inner surface of the new caps with oil, having previously removed the spring from them; Install the stuffing box into the frame and put it on the stem, and then press it in until it stops with weak blows; Put the springs on the caps and dry the valves in reverse order. If there is a possibility that the valve stem seals were faulty for a long time, you will need to remove the cylinder head and carry out a full replacement, with cleaning the engine elements from carbon deposits.

Does installing new caps always help?

Of course, replacing caps, especially if you do not remove the engine head, is not a panacea. It happens that the engine, even after replacing the valve stem seals, eats oil. In this case, there is a possibility that a mistake or negligence was made during operation. For example, the stuffing box is not fully pressed or completely torn. But, as a rule, the problem lies in the piston rings. The engine will have to be disassembled (remove the head), take out the pistons and change the piston rings. They change as a whole.

Sometimes it also happens that the car smokes after replacing the valve stem seals. In this case, the reason does not necessarily lie in the rings. Most often, this means that oversights were made during the repair: incorrectly sized caps, inaccurately installed or not replaced at all. If the caps are not fully pressed in, then they will fly off during operation with all the ensuing consequences, so to speak.

In rare cases, when the car smokes and consumes excess oil, decoking of the piston rings can help without replacing the valve stem seals. This procedure will require special fluid, which is poured into the wells of the spark plugs (after unscrewing the latter).

Before starting the procedure, you need to set all the pistons to approximately the same position. To do this, sticks of the same length are inserted into the candle channels and by rotating the shaft by the nut, they are aligned to one level. After that, the decarbonizer is poured into the holes.

After 4-6 hours, you need to remove the remaining fluid from the cylinders. To do this, the candle channels are covered with a rag and the engine is scrolled several times by the starter. Then the candles are screwed into place and the engine starts. It won't happen right away. It may take several tries. As it warms up, blue smoke will come out of the exhaust pipe. This is normal and disappears after the engine has warmed up for idling. As soon as it stops smoking, turn off the engine and immediately change the oil completely. The remains of coke deposits will burn out for another 100-200 km.

Difference between valve stem seals and valve stem rings.

Often inexperienced car owners ask how to determine what is on their car: rings or caps. The answer is that for optimum engine performance, both oil scraper rings, and caps. Rings remove oil residue from the moving piston and provide piston lubrication, while valve stem seals are mounted on the valve stems. In fact, both parts perform the same function: they protect the combustion chamber from oil.

The ingress of oil into the combustion chamber of the internal combustion engine is fraught with the appearance of soot on the valve and on the walls of the cylinder of the gas distribution chamber. As a result, the engine will run worse and fail faster. Among other things, the ingress of oil into the combustion chamber degrades the quality of the gasoline-air mixture and clogs the grooves of the piston rings.

What you need to pay attention to when buying valve stem seals:

Of course, it is recommended to use only those caps that are designed for a particular engine, but this is not always possible and advisable. Firstly, new caps on an old motor can be very useful and improve the fit, and secondly, original caps can be expensive or unavailable and it makes sense to order analogues if a replacement is needed here and now.

In order to choose the right cap and it did not jump off and fit in size, you must observe the following selection rules:

1. The analogue can be only 0.5 mm higher than the original. Otherwise, the spring plate may damage the cap.
2. The cap diameter must not be too large, it must pass freely through the valve spring.
Today, domestic manufacturers of caps are inferior to imported ones.

To avoid buying low-quality or counterfeit products, purchase valve stem seals and other spare parts in our online store. We guarantee correct selection spare parts and provide a replacement part or refund in case of marriage or incorrect selection.