Engines internal combustion, which are installed on modern cars, are quite complex mechanisms with many details. Therefore, for normal operation over a long period of time, they require proper maintenance.

Unfortunately, many motorists do not pay due attention to this. For example, they do not understand very well what valve adjustment is for and often ignore this procedure, which leads to additional breakdowns and high repair costs. In this article, we will talk about what valve adjustment is, which engines need it, and how it is performed.

Before answering the question of what valve adjustment is, you must first find out what the valves of internal combustion engines are, where they are located, and what functions are assigned to them. Structurally, these important parts of modern engines are cylindrical "plates" with fairly long rods. They are installed in the cylinder block, and in the amount of at least two for each of them. The valves in the closed state are adjacent to the seats, which are made of steel and are pressed into the cylinder head (cylinder head). Since these parts experience significant mechanical and thermal loads during operation, they are made of special steels that are resistant to such influences.

Valves are components of the gas distribution mechanisms of cars (timing), which are often called valve. They are divided into inlet and outlet. The function of the first is, as you might guess from the name itself, the inlet combustible mixture into the cylinders, and the second - the release of exhaust gases from them. During the operation of the engine, the valves expand, their rods lengthen, respectively, the size of the gaps that should be between their ends and pushing cams (in older engines - rocker arms) change. During the operation of the internal combustion engine, the dimensions of these deviations increase, and it is when they begin to exceed the maximum permissible values ​​that the valves should be adjusted. It consists in bringing the gaps back to normal.

If the valves are not periodically adjusted, then this can lead to very unfortunate consequences. In the case when the gap is too small, "burning" will inevitably occur. This means that a sufficiently dense layer of combustion products will form on the surfaces of the valves. fuel mixture. Because of it, the normal operation of the gas distribution system, and, consequently, the engine as a whole, is disrupted. In addition, this soot is quite difficult to remove.

In cases where the gap is excessively large, the valves do not open fully, and therefore engine power drops significantly. In addition, they begin to "knock", and this knock experienced drivers hear, even while in the cabin, driving your car. It goes without saying that increased valve clearances affect the operation of an internal combustion engine no less negatively than excessively small ones.

Which engines need valve adjustment and when?

It should be noted that not all internal combustion engines require periodic valve adjustment. The fact is that now in many modern internal combustion engines, which are equipped with cars, so-called hydraulic compensators are installed in the systems of their gas distribution mechanisms. These devices independently, in real time, adjust the gaps, and therefore their value is always optimal.

If there are no hydraulic lifters in the vehicle's engine, then the valves must be adjusted manually. The fact that the time has come to deal with this matter is quite easy to recognize by some of the symptoms. One of them is the characteristic "clatter" of the valves, which has already been mentioned above, and the other is that the engine begins to "troit", in its cylinders, either the compression drops significantly, or the compression completely disappears. As soon as at least one of these symptoms appears, it is necessary to check the dimensions of the gaps in the valve mechanism.

This should also be done without waiting for "alarm bells", as part of the ongoing maintenance of the car. Check frequency valve clearances indicated in the technical documentation for each vehicle, and, as a rule, is once every 25,000 - 30,000 kilometers. It is usually carried out at stations Maintenance, but, having certain skills, checking valve clearances can be done independently.

Valve Adjustment Procedure

It is necessary to adjust the valves only on a cold engine, and with strict adherence to a certain sequence of actions. Otherwise, the gaps will be adjusted incorrectly with all the ensuing consequences.

The adjustment process begins with the piston of the cylinder being set to the highest compression point. To bring it into this position, you need to turn crankshaft or for the starting handle, or for the screw securing the generator drive pulley. It should be noted that the rotation must be done only clockwise. After the piston is installed, it is necessary to check the clearance. This is done using a special probe.

If it turns out that the gap is either excessively large or too small, then it is necessary to change it. To do this, on the corresponding bolt or screw, you must first loosen the lock nut, and then set the gap to the required limit. It is determined by the thickness of the respective stylus. Once the gap is set, lock this position by tightening the locknut. This must be done carefully and carefully so as not to knock down the setting. After that, it is imperative to check the correct adjustment of the valve with a feeler gauge: it should enter the gap, but not freely, but with some effort. If this is the case, then this means that the adjustment of the specific valve of the specific cylinder is correct, and you need to do the entire procedure described above for all remaining valves and cylinders.

It should be noted that the adjustment of the valves of internal combustion engines is a very painstaking procedure, requires accuracy, and does not tolerate haste. It is best not to do it yourself, but to contact a service station and entrust this work to professionals with the appropriate experience and necessary skills.

Related video

The engine is the most important part of the car, on which the operation of the car is completely based. That is why it is important to monitor the condition of the engine, carry out diagnostics, and also change it in a timely manner. Consumables. Valves can be the cause of many problems in a car (for example, knocking, power loss). Therefore, it is important to know how to properly adjust the valves.

valves in cars

Each car has either 8 or 16 valves. Their number depends on the number of cylinders - either one valve per cylinder, or two. The first is responsible for launching the combustible mixture into the combustion chamber, the second is responsible for opening the outlet for the exhaust gases to exit. Such a mechanism that regulates the distribution of the mixture and gases is called gas distribution or valve. It is worth noting that different systems are installed on a diesel engine and an injector.
When the motor heats up, the metal expands. Thus, there must be gaps on the engine that have a fixed size. The consequences of improper valve adjustment include reduced engine efficiency, as well as rapid wear of parts.

For example: if the gap is insufficient, the valve will burn, if the gap is too large, the valve will not fully open and make a metallic knock.
How often should the valves be adjusted?
If you change the size of the gaps, you need to adjust them.

Signs of improper valve adjustment

There are a lot of signs that the gaps have been violated. First of all, the engine power and efficiency of its work are reduced. An unpleasant metallic knock, noise, burning smell, etc. may occur. Knock appears mainly under loads or on Idling. As a result, engine parts are subject to rapid wear.
The above signs of misadjusted valves are an alarming symptom. If at least one of them appears, it is necessary to check the valves and adjust them.

valve adjustment result

Valve adjustment: what is it for?

Ultimately, with proper valve adjustment, the stability of the motor is restored, power and wear resistance increase. The engine will run smoother and more stable at both low and high speeds.

Can the valves be adjusted?

V modern cars so-called hydraulic compensators are installed. V conventional engines there are cams camshaft or "pushers", which push the valve. As for the hydraulic compensators, they themselves find the necessary clearance for the release of gases at high oil pressure. They provide optimal performance valves in any case. Many people ask: “If you don’t adjust the valves, what will happen?” If the car has hydraulic lifters, then valve adjustment is not necessary. Otherwise, the valves should be adjusted and checked periodically.

How to adjust valves?

How to properly adjust valve clearances

Many car owners try to adjust the valves themselves without contacting technical service.
It is necessary to set the dimensions of the gaps on the engine in a cold state, since the factory settings were made on cold metal. In this case, it does not change its dimensions, and they remain standard.
It is worth noting that it is worth adjusting the valves exactly according to the recommendations and instructions, otherwise the gaps will be set incorrectly.
First, the cylinder piston is set to the dead center of the compression stroke at the top. The cylinder clearance will be determined with a feeler gauge. This will ensure that both valves close and that the rocker arm swings within the specified clearance limits. Manufacturers usually put marks on which you can install the piston in this position.
The adjustment itself is made by turning the screws of the rocker arms in the right direction. Turn the crankshaft asterisk only clockwise. Many apply their marks to determine the position of each of the cylinders. The marks must match on the bearing and crankshaft.
Next, you need to release the locknut on the bolt or screw. The gap must be set to the limit, in this case, which is the probe. Then it is necessary to fix the position by tightening the nut. This should be done carefully, taking into account the tightening force, since the established gap can be knocked down. To check the gap, you need to insert the probe, it should pass, but with effort. If the probe does not pass, you need to repeat the adjustment.

It is necessary to adjust the valves one by one in the order in which the cylinders in the car work, and with the utmost care.

The crankshaft is rotated only by the starting handle (crooked starter handle), or by the screw securing the generator drive pulley, and only clockwise.
Here you definitely need a probe or a special tool for adjusting the valves.
In special books on engine repair, the adjustment procedure is fully described. Another feature is the setting of the gap on the intake and exhaust valves. The boost pressure control valve has a clearance different from the exhaust. In addition, different clearances may be required for different cylinders. All this is described in the car repair manual.

Required Tools

What you need to adjust the valves

As mentioned earlier, a probe or special tool is required. If you choose the right one, you can work with adjustment plates. A rail is often used to adjust valves, which provides greater accuracy than plates or a feeler gauge. However, the adjustment process itself is different, it does not correspond to the above method.
You can use an indicator. It is a special device for adjusting valves with high precision.

Thus, the valves are responsible for the distribution of the combustible mixture in the engine, the timely release of exhaust gases. Valve clearances should be monitored regularly and adjusted if necessary. You can adjust the valves yourself, without resorting to the services of car services. It is important to accurately measure valve clearances, as they ensure the stability and efficiency of the engine.

5 years ago

Welcome!
Valve adjustment - most people, of course, know what this process is and why it needs to be done regularly on some cars, for example, on the Classic, but there are people who don’t know anything about it and want to understand this issue, therefore, especially for such people this article was prepared from which you will learn a lot. And if something becomes unclear to you, then in this case, write a comment with your question at the very bottom of the site and we will answer it as soon as possible.

Note!
And in addition, at the end of the article, an interesting video clip awaits you, thanks to which you will understand a lot for yourself in adjusting the valve drive!

Why do you need to adjust the valves?

Their adjustment is necessary in order for the machine to work more stably both at high and at low revs engine. Because, as a rule, due to incorrect adjustment of the valves, the gaps that should be between the camshaft cam and the valve itself are violated, which leads to too much opening of the valve during engine operation and, as a result, depressurization will occur in the cylinder, which in turn can adversely affect the engine life .

Note!
In the event that the gap between the valve seat and the side particles of the cylinder has become very large (see photo below, this gap is marked there), then in this case the valve may burn out, and also if the piston stroke is very large, then meeting of valves with the piston itself during engine operation. Therefore, the valves must be adjusted periodically and with great care, since incorrectly set gaps during adjustment can again adversely affect the motor resource!

How will the valves work if the clearance is incorrectly set?

In this case, as mentioned earlier, the operation of the valves is disrupted, in connection with this, the valves either begin to open a little more than expected, or they begin to be in a constantly open position, due to which the sealing in the cylinder disappears, for clarity, look at the photo below on which the valve adjustment is violated and in connection with which the valve is in a permanently open mode.

How to get rid of valve adjustment?

Have you ever asked yourself: “Why, for example, on a 16-valve prior, do you not need to adjust the valves?” And the thing is that in the priors engine, instead of the “Pusher”, due to which the camshaft cam pushes the valve, there are “Hydro-compensators”, which, in turn, due to the high oil pressure, find the optimal gap between the cam and the “Hydro-compensator” itself valves and therefore valves always operate at optimum clearances.

Note!
By the way, "Hydro-compensators" can be installed on almost any car, and therefore you can forget about valve adjustment, but there is one But! "Hydro-compensators" can only be installed on cars in which the "Gas Distribution Mechanism - aka Timing" consists of a camshaft, crankshaft, as well as valves and piston group- in fact, this is the main part of the car!

The question of the correct performance of the car worries every motorist, because the good operation of the car and a long service life depend on it. Many drivers are interested in the question - when to do the alignment, since there are many disputes and different opinions about this. To know for sure, you need to know general concepts how the car is arranged and some data about wheel alignment. Let's talk about this in more detail.

Many service stations carry out car data analysis negligently to make their work easier. They do not take into account the fact that a car with a loaded trunk behaves differently and it is important to test it not only in an easy position, but also with a load. The pressure level in the tires is also very important, but few mechanics first measure these values. Therefore, if a motorist decides to contact the service station to the masters, carefully analyze the actions of these specialists and require the correct implementation of all procedures.

This procedure will have to be performed in case of obvious defects in control (the car leads to the side), when changing components that affect performance, with frequent driving on bad roads and when high mileage no service.

A caring driver will ask the master at the service station: when should the camber be done? He will answer him that every half a year, or even more often. Since the more visits the motorist makes to the workshop, the more income it will receive. If the driver asks the seller a question in car showroom: when to do the collapse? He will most likely answer that no more than once every few years, to recommend the car, show it strengths and minimum costs for service.

Therefore, each car owner must monitor his car on his own. Only you, and no one else, knows how the car drives, where and when it pulls, what is its exact mileage and what roads it traveled on.
Then, when it is necessary to do a collapse, the car will “tell” itself, although it is possible to test it or look at the integrity of the component parts once every half a year.

The basic rules that you should know about when to do the collapse of the convergence:

If you have an old car, you need to check the alignment more often, if you have a new one, less often, the owner knows better. The main thing in this matter is to understand that if the wheel is worn out, it is worth considering other characteristics of the car that may also wear out, but they are not visually visible. Good luck in the difficult automotive business!