How many valve stem seals are in the engine. Replacement of valve stem seals. Advice. Increased fuel consumption

Insufficient valve closure leads to the formation of varnish deposits in the cylinder head and on the piston group.

Criteria for wear on stuffing boxes:

• regular occurrence of carbon deposits on spark plugs;
• overestimated consumption of engine oil;
• lack of stable idle speed;
• with a sharp increase in speed - abundant emission of gray smoke.

Passing Maintenance includes regular replacement of oil, air, oil and fuel filters. Valve oil seals are designed for vehicle operation up to 100,000 km. In fact, the replacement has to be carried out earlier than the specified resource.

The device of the valve stem seals (valve seals)

The oil scraper seal is in the form of a frusto-cone cylinder. For tight contact with the surface of the valve guide, a polymer ring with an expander spring is provided. A plastic (or rubber) ring removes excess oil as the valve stem moves, and a spring allows it to firmly lock onto the stem.

For a long time, a rubber ring has been used in the design of the stuffing box. Variants from rubber and fluoroplastic have appeared recently. This is due to the fact that rubber dubs faster and loses its properties. The production of the ring using modern polymers prolongs the life of the stuffing box.

Purpose of valve stem seals

Long uninterrupted work ICE is provided high-quality lubricant rubbing parts. The oil distribution mechanism provides a small amount of oil. The camshafts in the cylinder head and the piston group require constant lubrication. The shaft rotates and a cloud of oil forms around it. The amount of lubricant is regulated by the valve stem seals.

Carbon deposits on the valve surface lead to incomplete closure and a gap. In the combustion chamber, the combustible mixture is ignited, and the excess oil settles in the form of varnish deposits. When the valve is pushed down, the stem packing prevents excess oil from entering. Protects the piston group from plaque arising from the combustion of oil and fuel mixture. The valve stem seals are considered consumable items, as they need to be periodically replaced.

The location of the valve stem seals in the engine

A head with camshafts and valves is installed on the cylinder block. The valve stem moves through the guide sleeve. The thermal gap between the stem and the sleeve is closed with caps. The oil seal is positioned so that oil from the head does not get into the combustion chamber. The camshaft journals receive oil under pressure, and the rest of the units are sprayed. Removing the engine block head and camshafts, you can see the location of the stuffing boxes in the valve seats.

Signs of wear on valve stem seals

You can find out about the need for replacement without disassembling the engine. Have valve stem seals the following signs of wear:

• excessive oil consumption;
• bluish smoke;
• carbon deposits on spark plugs.

When the oil seals are worn, oil consumption increases. This also happens with "coking" piston group but there is a visual difference. Oil drips are noticeable on the breather pipe. Blue smoke is a sign that oil is entering the combustion chamber. "Troening" of the engine and carbon deposits on the spark plugs are justified by the flow of oil through the stem oil seal. The car needs diagnostics and oil seals replacement.

The service life of the oil scraper does not depend on the price and manufacturer. For budget and "premium" cars, the resource is designed for mileage up to 100,000 km.

The procedure for replacing the valve stem seals

1. Detach air filter, removing the cover and air ducts. The branch pipes and technical openings are closed with plugs. Unscrew the candles and cylinder head bolts.
2. The piston in the first cylinder is set at top dead center. Removing the lock washer and star. The locknuts of the valves are allowed, and the regulating nuts are unscrewed until they stop.
3. Crackers and springs are removed. The oil seals are removed with a puller. The bushings are lubricated with oil, slid onto the stem and installed with a hammer and rim.
4. Assemble units and parts in reverse order. After, the remaining caps are changed in the order of cylinders 4 - 2 - 3 by a similar algorithm.

Servicing each cylinder requires a 180 degree crankshaft rotation.

Self-replacement will require a special tool. The main specific device is a valve “desiccant”. It will be needed to replace the valve oil seal. Devices and materials:

• sets of socket and spanner wrenches;
• extension cord with heads;
• rod and hammer;
• Collet clamp;
• press frame;
• tweezers;
• head gasket;
• a set of new caps;
• sealant.

During the work, it is possible to replace the gaskets for the block and the cylinder head. New oil seals are selected for a specific engine model.

The procedure for replacing the valve stem seals

Consider how the valve stem seals are replaced by 8 valve engine without removing the head:

1. We shoot fuel pump and an air filter.
2. Turn off the battery power and dismantle the ignition distributor.
3. We unscrew the top cover of the block, disconnect toothed pulley and mass.
4. Unscrew and remove the nuts on the camshaft and bearings evenly.
5. We dismantle shafts and oil seals.
6. By turning crankshaft, raise the piston at TDC on the serviced cylinder.
7. Insert a soft tin rod under the valve through the hole for the candle.
8. We remove the springs with a special device and remove the plates. We replace the oil seals by pressing the old ones from the bushing and installing new ones.
9. Let's reassemble in the reverse order. We proceed to a consistent similar replacement on the remaining cylinders.

The caps are lubricated with oil before being installed in the frame. They are pressed into the plate carefully, without sharp strong impacts.

Gaskets and seals are installed under the bolt heads. Sort small items to avoid losing them.

After replacing all valve seals, reassemble the head by placing it on sealant and a new gasket. Tighten the nuts with a specified torque, according to the instruction manual for this engine.

The valve packing kits differ in design for different engines. Installation is carried out according to technical recommendations for a specific car model. When carrying out work yourself, adhere to the accuracy:

• coincidence of the diameters of the sleeve belt and the valve stem;
• the length of the seats of the guide sleeve and cap;
• oil installations with reliable fixation (without the slightest backlash);
• selection of a set of caps for a specific engine model.

The high class of precision in the manufacture of parts allows to increase the density of the connection and the complete coincidence of dimensions.

On sale there are additives for the restoration of oil seals. Their principle of action is to soften the hardened rubber of the sealing ring. Manufacturers differ in the quality of manufacture of additives. There are various effects on rubber: no effect or excessive softening, which leads to excessive consumption of oil.

The combustion chamber of the car must be protected from the ingress of foreign substances and elements. The valve stem seals are responsible for this, the task of which is to prevent excess oil, shavings and other "debris" from entering the combustion chamber during the movement of the valve rods of the car. If the valve stem seals have ceased to cope with their tasks, they must be urgently replaced in order to avoid carbon deposits on the engine elements, as well as increased oil consumption. In this article, we will look at what signs indicate wear on the valve stem seals, why they wear out, and how to replace them without removing the cylinder head.

Why do you need valve stem seals

The operation of the engine assumes the non-stop operation of the elements of the gas distribution mechanism of the car. To reduce their wear due to friction, oil is supplied to the timing belt, which should not be in the combustion valve, otherwise the stable operation of the motor will be disrupted. During valve operation, the valve stem seals take on the task of removing excess oil and act as an obstacle, preventing oil from entering the combustion chamber.

The valve stem seals are arranged quite simply, and there are 3 main components of which they consist:

• Base. A sleeve made of steel, which is the frame of the cap and gives it strength;
• Spring. It is necessary to create the most tight fit of the cap edges to the stem;
• Cap. The main element of the part, made of rubber or second-grade resin (older models). Its task is to remove excess lubricant from the valve stem.

It is worth noting that valve stem seals have changed a lot in terms of the materials used over the past decade. Since their failure can lead to big problems, manufacturers strive to use the most durable and wear-resistant materials that are resistant to aggressive environments.

Service life of valve stem seals

It is easy to guess that valve stem seals need to be changed from time to time. The valve performs more than 1000 strokes per minute, and on each valve stem seals must remove excess oil to prevent it from entering the combustion chamber. It should also be borne in mind that the temperature in the operating area of ​​the valve stem seals is high, and the medium itself is aggressive: oil and exhaust gases.

Due to the influence of a mass of factors, the valve stem seals begin to deteriorate over time - the rubber of the cap cracks, peels off, loses its elasticity. Over time, the spring begins to press the cap less tightly against the walls, which is why oil begins to enter the combustion chamber.

Average life of valve stem seals good quality is at 100,000 kilometers. If the car has been idle for several years, it is recommended to replace the valve stem seals before starting to operate it, since during the idle time they have time to dry out.

Signs of wear on valve stem seals

If the valve stem seals are worn out early and replaced in time, serious engine problems can be avoided. The primary signs of valve failure are as follows:

• Dense blue or white smoke comes out of the vehicle exhaust;
• Oil consumption increases significantly;
• Carbon deposits form on the spark plugs.

When the above-described signs of wear on the valve stem seals appear, an urgent need to inspect them, as well as check the gas distribution mechanism and valves. If there are traces of strong wear on the valve stem seals, they must be replaced, otherwise:

• Engine power will begin to decrease;
• The car will stall for Idling, or the revolutions will start to "float";
• Compression in the engine will decrease;
• Carbon deposits will form on the pistons and cylinders, and the valves will no longer provide tightness due to poor closure.

Carbon deposits on engine elements are a direct road to an early overhaul. Timely replacement of valve stem seals with new ones will help to avoid this.

How to replace valve stem seals without removing the cylinder head

If the problem with the wear of the valve stem seals was detected in a timely manner by the driver, he can replace them without removing the cylinder head. In a situation where the solution to the problem was 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 the valve stem seals will differ. But there are several main stages that are common to all machines:

If there is a possibility that the valve stem seals were faulty for a long time, it will be necessary to remove the cylinder head and carry out a full replacement, with cleaning the engine elements from carbon deposits.

September 24, 2017

In the design of any engine, and domestic car, and foreign cars, there are valve stem seals (valve seals). They are always used when the machine is running, and therefore wear out very quickly. Increasing their service life is a headache for engineers working at automobile factories, but the timely diagnosis of signs of wear on valve stem seals, as well as their replacement, is already the task of motorists. You can cope with it successfully only in one case when these very signs are known to you, and if not, then this article will help you.

HOW VALVE SEALS WORK AND WHEN THEY COUNT Worn out

As you know, the valve in the engine is located in two different cavities. One of them implies the presence of engine oil in it, the other, on the contrary, must be isolated from it. In this case, the valve is in constant motion during its operation.

WHAT YOU NEED THE VALVE SEALS FOR

They are made of special elastic rubber, but this rubber tends to age, harden, dry out and collapse over time, as a result, the caps cease to cope with the task assigned to them and begin to need replacement. The car owner can determine this moment by special characteristics.

Worn valve stem seals

MAIN SIGNS OF VALVE SEAL WEAR

1. Increased oil consumption - if engine oil is consumed in your car more than it should be, which means that somewhere it is used in vain, as an option, it gets into the combustion chamber due to worn out valve seals.
2. Spark plug oil deposits are caused by oil entering the cylinders.
3. when the car warms up, the engine heats up - the smoke disappears. This phenomenon is a clear sign of a cracked cap, which, heating to a certain temperature, becomes wider and begins to successfully cope with the functions assigned to it again.

However, be extremely careful, these signs may indicate not only worn valve stem seals, but also other problems with the engine! Therefore, at the time of diagnosis, do not forget to pay attention to:

• mileage - as a rule, oil seals need to be replaced every 70-80 thousand km. mileage;
• compression - if it is reduced, but you did not find any leaks or problems with valves and / or rings on the pistons, then the problem is definitely in the caps. They should be replaced.

EFFECTS OF RIDING WITH WEARED OIL SEALS

If you missed the moment of failure of the valve seals, then, most likely, it will lead to the following consequences:

• increased oil consumption, which, firstly, will not have the best effect on your budget, and secondly, it will provoke periodic oil starvation, leading to increased wear of parts and the need for premature overhaul engine;
• oily and ultimately spark plug failure;
• burnout of valves - carbon deposits will form wherever there is oil, including on the cylinder walls, which over time will interfere with the closing of the valves and lead to their burnout.

To prevent all this from happening, carry out a timely replacement as soon as you notice the first signs of wear on the valve stem seals.

OIL SEAL REPLACEMENT TIPS

We will not consider the procedure for replacing the valve stem seals now, this is a topic for a separate article, but we will finally name the main recommendations that will save you from mistakes. There are only 3 of them:

1. to dry the valves, always use a special tool - a desiccant, so you will have less chance of breaking or losing something;
2. when changing the caps, cover all openings on the engine with a rag or foam rubber, they will protect open cavities from dirt and you from losing crackers;
3. Be sure to lubricate the new cap with oil before installing.

And remember, if you do not have enough experience and knowledge in the matter of replacing valve seals, noticing signs of wear, do not experiment, but hand your car into the hands of professionals, they will quickly replace the failed parts with new ones and take a little in this case. Depending on the car and service station, the costs will be from 7 to 20 thousand rubles.

The valve stem seals, or valve seals as they are also called, 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 the valve stem seals are, but also the reasons and the first signs of their wear.

What are valve stem seals.

Valve 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 play.

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

• Base;
• The cap itself;
• Spring.

The base is a bushing 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 of special rubber that is resistant to high temperatures and frictional forces. The cap is seated 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 the most tight fit to the stem.

As for the oil, which these caps must remove, it is supplied to the gas distribution mechanism by an oil pump. It is designed to lubricate the timing parts experiencing friction and increase their resource. At the same time, its penetration into the cylinders through the valve groups is extremely 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 stress. In addition, they are negatively affected by the substances contained in the removed lubricant. Therefore, manufacturers of valve stem seals use the most durable materials that are resistant to friction, thermal and chemical influences.

The location of the valve stem seals in the engine

A head with camshafts and valves is installed on the cylinder block. The valve stem moves through the guide sleeve. The thermal gap between the stem and the sleeve is closed with caps. The oil seal is positioned so that oil from the head does not get into the combustion chamber. The camshaft journals receive oil under pressure, and the rest of the units are sprayed. After removing the engine block head and camshafts, you can see the location of the oil seals in the valve seats.

Worn valve stem seals

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

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

In addition, it often happens that the 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:

• Carbon deposits on spark plug electrodes;
• The emergence exhaust gases blue when the engine is warming up.

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

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

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

The consequences of wear on the valve stem seals

As soon as the listed signs of wear on 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 categorically 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;
• At idle speed, it will periodically stall;
• Turnovers will "float";
• Compression will drop significantly;
• Carbon deposits will form on cylinders, pistons and valve seats.

As for carbon deposits, its appearance is indeed a very serious "bell", since its formation may well lead to a very expensive overhaul of the 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 a timely manner by the driver, he can replace them without removing the cylinder head. In a situation where the solution to the problem was 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 the valve stem seals will differ. But there are several main stages that are common to all cars: Before starting to replace the valve stem seals, you need to let the car's 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 springs of the valve are dismantled - "dry up"; 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, after removing the spring from them; Install the oil seal in the frame and push it onto the stem, and then press it in until it stops with weak blows; Put the springs on the caps and dry the valves in the reverse order. If there is a possibility that the valve stem seals were faulty for a long time, it will be necessary 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 the caps, especially if you do not remove the engine head, is not a panacea. It so happens that the engine eats oil even after replacing the valve stem seals. In this case, there is a possibility that a mistake or negligence was made during the work. For example, the oil seal is not completely pressed in or is completely torn. But, as a rule, the problem lies in the piston rings. The engine will have to be disassembled (remove the head), remove the pistons and change the piston rings. They change as a whole set.

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 mistakes were made during the repair: caps that were incorrectly selected in size, inaccurately installed or not replaced at all. If the caps are not pressed in completely, then during operation they will fly off with all, so to speak, the ensuing consequences.

In rare cases, when the car smokes and consumes oil in excess, decarbonization can help without replacing the valve stem seals piston rings... This procedure will require special liquid, 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, their alignment is achieved by one level. After that, the decoking machine is poured into the holes.

After 4-6 hours, the remaining fluid must be removed from the cylinders. For this, the spark plug 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. This will not happen immediately. It may take several tries. In the process of warming up from exhaust pipe will bring down gray smoke. This is normal and disappears after the engine has warmed up for idle... As soon as the smoke stops, the engine must be turned off and the oil must be completely changed immediately. 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 optimal engine performance, both oil scraper rings and caps. Rings remove residual oil from the moving piston and provide piston lubrication, while valve stem seals are fitted to the valve stems. In fact, both parts perform the same function: they protect the combustion chamber from oil ingress.

Oil getting into the combustion chamber of the internal combustion engine is fraught with carbon deposits on the valve and on the cylinder walls of the gas distribution chamber. As a result, the engine will work worse and fail faster. Among other things, oil entering the combustion chamber degrades the quality of the gasoline-air mixture and clogs the piston ring grooves.

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 helpful and will improve the fit, and secondly, original caps may be expensive or unavailable and it makes sense to order analogs if replacement is needed here and now.

In order to select the desired cap and it did not jump off and fit in size, the following selection rules must be observed:

1. The analog can be only 0.5 mm higher than the original. Otherwise, the spring plate may damage the cap.
2. The diameter of the cap cannot 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 will provide replacement parts or reimbursement in the event of a defect or incorrect selection.

In the design of any engine, both a domestic car and a foreign car, there are valve stem seals (valve seals).

They are always used when the machine is running, and therefore wear out very quickly. Increasing their service life is a headache for engineers working at automobile factories, but the timely diagnosis of signs of wear on valve stem seals, as well as their replacement, is already the task of motorists. You can cope with it successfully only in one case when these very signs are known to you, and if not, then this article will help you.

How do valve stem seals work and when are they considered worn out?

As you know, the valve in the engine is located in two different cavities. One of them implies the presence of engine oil in it, the other, on the contrary, must be isolated from it. In this case, the valve is in constant motion during its operation. In order to maintain the tightness of the hole through which it moves from one medium to another, valve stem seals are just needed. They are made of special elastic rubber, but this rubber tends to age, harden, dry out and collapse over time, as a result, the caps cease to cope with the task assigned to them and begin to need replacement. The car owner can determine this moment by special characteristics.

The main signs of wear on the valve stem seals.

1. Increased oil consumption - if the engine oil is consumed in your car more than it should be, it means that somewhere it is used in vain, as an option, it gets into the combustion chamber due to worn out valve seals.
2. Spark plug oil deposits are caused by oil entering the cylinders.
3. Blue exhausts when the car warms up, the engine heats up - the smoke disappears. This phenomenon is a clear sign of a cracked cap, which, heating to a certain temperature, becomes wider and begins to successfully cope with the functions assigned to it again.

However, be extremely careful, these signs may indicate not only worn valve stem seals, but also other problems with the engine! Therefore, at the time of diagnosis, do not forget to pay attention to:

• mileage - as a rule, oil seals need to be replaced every 70-80 thousand km. mileage;
• compression - if it is reduced, but you did not find any leaks or problems with valves and / or rings on the pistons, then the problem is definitely in the caps. They should be replaced.

Consequences of driving with worn valve stem seals.

If you missed the moment of failure of the valve seals, then, most likely, it will lead to the following consequences:

• increased oil consumption, which, firstly, will not have the best effect on your budget, and secondly, will provoke periodic oil starvation, leading to increased wear of parts and the need for premature engine overhaul;
• oily and ultimately spark plug failure;
• burnout of valves - carbon deposits will form wherever there is oil, including on the cylinder walls, which over time will interfere with the closing of the valves and lead to their burnout.

To prevent all this from happening, carry out a timely replacement as soon as you notice the first signs of wear on the valve stem seals.

We will not consider the procedure for replacing the valve stem seals now, this is a topic for a separate article, but we will finally name the main recommendations that will save you from mistakes. There are only 3 of them:

1. to dry the valves, always use a special tool - a desiccant, so you will have less chance of breaking or losing something;
2. when changing the caps, cover all openings on the engine with a rag or foam rubber, they will protect open cavities from dirt and you from losing crackers;
3. Be sure to lubricate the new cap with oil before installing.

And remember, if you do not have enough experience and knowledge in the matter of replacing valve seals, noticing signs of wear, do not experiment, but hand your car into the hands of professionals, they will quickly replace the failed parts with new ones and take a little in this case. Depending on the car and service station, the costs will be from 7 to 20 thousand rubles.

Video.