Internal combustion engines that are installed in modern cars are quite complex mechanisms with many parts. Therefore, they require proper maintenance to function properly over a long period of time.

Unfortunately, many motorists do not pay due attention to this. For example, they do not very well understand why valve adjustment is needed and often ignore this procedure, which leads to additional breakdowns and high repair costs. In this material 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 they are assigned to perform. Structurally, these important parts of modern engines are cylindrical “plates” with fairly long rods. They are installed in the cylinder block, and there are at least two for each of them. When the valves are closed, they are adjacent to seats, which are made of steel and pressed into the cylinder head (cylinder head). Since during operation these parts experience significant mechanical and thermal loads, they are made of special steels that are resistant to such influences.

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

If the valves are not periodically adjusted, this can lead to very unhappy consequences. In the case when the gap is too small, “burning” will inevitably occur. This means that a fairly dense layer of combustion products of the fuel mixture will form on the surfaces of the valves. Because of it, the normal operation of the gas distribution system, and, consequently, the engine as a whole is disrupted. In addition, this deposit 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 experienced drivers hear this knock even while in the cabin while driving their 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 that are equipped with passenger cars, so-called hydraulic compensators are installed in the systems of their gas distribution mechanisms. These devices independently adjust the gaps in real time, and therefore their value is always optimal.

If the vehicle engine does not have hydraulic compensators, then the valves must be adjusted manually. It’s quite easy to know that it’s time to do this by looking at some symptoms. One of them is the characteristic “clicking” of the valves, which was already mentioned above, and the other is that the engine begins to “trouble,” and compression in its cylinders either drops significantly or completely disappears. As soon as at least one of these symptoms appears, it is necessary to check the size of the gaps in the valve mechanism.

This should also be done without waiting for “alarm bells”, as part of routine vehicle maintenance activities. The frequency of checking valve clearances is 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 service stations, but, with certain skills, you can check the valve clearances yourself.

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 cylinder piston being set to its highest compression point. To bring it to this position, you need to turn the crankshaft either by the starting handle or by the screw securing the generator drive pulley. It should be noted that rotation should only be done clockwise. After the piston is installed, it is necessary to check the gap size. This is done using a special probe.

If it turns out that the gap is either too large or too small, then it needs to be changed. To do this, you must first release the lock nut on the corresponding bolt or screw, and then set the gap to the required limit. It is determined by the thickness of the corresponding probe. Once the gap value is set, you need to fix this position by tightening the lock nut. This must be done carefully and carefully so as not to disrupt the setting. After this, you must definitely check the correct adjustment of the valve using a feeler gauge: it should fit into the gap, but not freely, but with some force. If this is the case, then this means that the adjustment of a particular valve of a particular cylinder was made correctly, and you need to do the entire procedure described above for all remaining valves and cylinders.

It should be noted that adjusting the valves of internal combustion engines is a very painstaking procedure, requires care, and cannot be rushed. It is preferable not to do it yourself, but to contact a service station and entrust this work to professionals who have the appropriate experience and necessary skills.

Video on the topic

Many motorists have encountered the process of adjusting VAZ-2114 valves at a car service center or carried out this operation with their own hands. But not everyone knows after what period of time this operation must be performed.

The video below will tell you about adjusting the valves on the VAZ-2114:

Diagram of the valve and elements for adjustment

Valve clearance adjustment process

According to regulatory technical documentation and the practice of motorists, the valves must be adjusted every 15,000-20,000 km or when the need arises.

Adjusting washer. It is used to adjust the valve clearance

To adjust the valves, special shims are used. There are 125 sizes, but only a small number have found use.

Let's consider which ones: 3.30, 3.35, 3.40, 3.45, 3.50, 3.55, 3.60, 3.65, 3.70, 3.75, 3.80, 3.85, 3.90, 3.95, 4.00, 4.05, 4.10, 4.15, 4.20, 4.25, 4.30, 4.35, 4.40, 4.45, 4.50;

Consequences of untimely adjustment

It is known that untimely carrying out any operation to repair and maintain a car entails certain consequences, which can be, in one case, mild, and in another, fatal for the power unit. So, let's look at the main ones:

1. Worn parts and assemblies of the cylinder head, namely the gas distribution mechanism.
2. Wear of camshafts.
3. Partial or complete destruction of pushers.
4. In a separate case, it leads to a broken timing belt and corresponding consequences, such as. !

conclusions

The valves on the VAZ-2114 should be adjusted no later than after 20,000 km. Untimely adjustment work can lead to unexpected and destructive consequences. Therefore, the car owner must follow the manufacturer’s recommendations.

To determine the dynamic properties of an object in practice, the method of removal is most often used. When determining an object by its (), either a stepped test signal or a rectangular pulse is supplied to the input - see section 2.3. In the second case (the response curve) must be built up to the appropriate one. The process of obtaining an object based on data about the transient process is called object identification.

When removing the transient response, a number of conditions must be met,
presented in table1:

Table 1 - Conditions for taking the transient response

No	Conditions
1	If a system for stabilizing a process parameter is being designed, then the transient response should be measured in the vicinity of the operating point of the process.
2	Transient characteristics must be taken both during positive and negative jumps of the control signal. By the appearance of the curves one can judge the degree of asymmetry of the object. If the asymmetry is small, it is recommended to calculate the controller settings using the average values ​​of the transfer function parameters. Linear asymmetry most often manifests itself in thermal control objects.
3	If there is a noisy output, it is advisable to take several transient characteristics (acceleration curves) and then superimpose them on each other and obtain an average curve.
4	When taking the transient response, it is necessary to select the most stable process modes, for example, night shifts, when the effect of external random disturbances is unlikely.
5	When taking the transient response, the amplitude of the test input signal must, on the one hand, be large enough so that the transient response can be clearly distinguished from the background noise, and, on the other hand, it must be small enough so as not to disrupt the normal course of the technological process.

Note to table1:

Initial conditions for taking the transient response:
At the initial moment, it is necessary that the control system be at rest, i.e. adjustable variable X(for example, temperature in the furnace) and the control action of the regulator Y(the output of the regulator to the actuator) did not change, and there were no external disturbances. For example, the temperature in the furnace remained constant and the actuator did not change its position. Then a step action is applied to the input of the actuator, for example, the heater is turned on. As a result, the state of the object begins to change.

Determination of dynamic characteristics of a self-leveling control object based on its transient response

Self-leveling regulation process is the property of a regulated object, after an imbalance between inflow and flow, to return to this state independently, without the participation of a person or regulator. Self-leveling promotes faster stabilization of the controlled variable and, therefore, facilitates the operation of the controller. The process of changing a parameter X(t) and its transient response h(t) is shown in Fig. 1. By removing , and assessing the nature of the control object (with or without self-leveling), you can determine the parameters of the corresponding .

It is recommended to use for control objects with a clearly expressed prevailing time constant. Before starting processing, it is recommended to normalize the transition characteristic (acceleration curve) (the range of variation of the normalized curve is from 0 to 1) and extract the value of the pure time delay from its initial section.

When applying a step effect to the input of some object, it was obtained
transient response (see example in Fig. 1). It is required to determine the parameters of the transition
characteristics.

Objects are identified using the acceleration curve method
tangent to a point transition characteristic (acceleration curve). In this case, the point corresponds to the transition of the curve from the acceleration mode to the deceleration mode of the rate of increase of the output signal.

Figure 1 - Transient response (acceleration curve) of an object with self-leveling

By the type of transient response, one can determine the dynamic properties of the object: K, Khust, ?d, T, R.

R = Xust / T

Determination of the dynamic characteristics of the control object without self-leveling based on its transient response

Figure 2 - Transient response (acceleration curve) of an object without self-leveling

For objects without self-leveling, stable operation of the system without a regulator is impossible. For objects without self-leveling gain is defined as the ratio of the steady-state rate of change of the output value X to the magnitude of the input signal jump U:

The magnitude of the dynamic delay in the object is determined as shown in Fig. 2. For regulators with a relay output, 100% of the power is supplied to the object. In some cases, prolonged exposure to such power is unacceptable. In this case, it is allowed to turn off the heating element after determining and R. In this case, the rate of temperature change can be determined quite accurately after reaching the value X values?0.3Hust. Then the rate of temperature change R and time constant T are determined by formulas.

The issue of proper car performance worries every car enthusiast, because good car performance and a long service life depend on this. Many drivers are interested in the question of when to do wheel alignment, since there are many disputes and different opinions on this matter. To make an accurate decision, you need to know general concepts, how a car works and some data about wheel alignment. Let's talk about this in more detail.

Many service stations analyze car data carelessly to make their work easier. They do not take into account 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 tire pressure level is also very important, but few mechanics measure these values ​​first. Therefore, if a car enthusiast decides to go to a service station and see the experts, carefully analyze the actions of these specialists and demand that all procedures be carried out correctly.

This procedure will have to be performed in case of obvious defects in control (the car is pulling to the side), when changing components that affect performance, when driving frequently on bad roads and when driving for a long time without maintenance.

A caring driver will ask the mechanic at a service station: when is it necessary to do a wheel alignment? He will answer him that every six months, or even more often. Because the more visits a motorist makes to a workshop, the more income it will receive. If a driver asks a question to a salesperson at a car dealership: when should a wheel alignment be done? He will most likely answer that no more than once every few years, in order to recommend the car, show its strengths and minimal maintenance costs.

Therefore, every car owner must take care of his car independently. Only you, and no one else, knows how the car drives, where and when it pulls, what its exact mileage is and what roads it drove on.
Then, when it is necessary to do a wheel alignment, the car itself will “tell”, although you can test it or look at the integrity of the component parts once every six months.

Basic rules that you should know about when to do a wheel alignment:

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

The wheel alignment procedure is performed to eliminate and prevent problems with vehicle handling. If the wheels are set up incorrectly, the car will react weaker to steering wheel movements, have difficulty making turns, and the problem of rapid tire wear will arise (in some cases, the wear threshold can be 500 km). Currently, wheel alignment is adjusted only at specialized service stations. Contrary to the opinion of some car owners, this procedure cannot be performed at home.

What is wheel camber?

Camber is the angle of deflection of wheels along the vertical axis. Positive camber occurs if the angle formed by the upper parts of the wheels is greater than the lower ones. This camber is used on trucks traveling in a loaded state, which compensates for the difference in angles. Negative camber occurs when the angle of the upper parts of the wheels is less than the lower ones. This camber is used to stabilize the car when cornering at high speeds. The most preferable is zero camber, in which the angles of the upper and lower parts of the wheels are the same. This camber ensures the handling of a city car and reduces tire wear. Wheel toe can also be positive or negative. With positive toe-in, the front parts of the wheels are at a smaller distance than the rear parts. When negative, on the contrary, the rear parts of the wheels are closer. Correct toe adjustment is extremely important, since incorrectly adjusted toe can increase tire wear several times.

Signs of an incorrectly set wheel alignment:

Despite the fact that wheel alignment is adjusted only with professional equipment at a service station, you can independently diagnose the correctness of its adjustment. Below we present several signs that indicate the need for wheel alignment adjustment:

• squealing noise occurs when cornering at high speed
• the car moves in a straight line only after the steering wheel is turned to the side
• Without fixing the steering wheel, the car pulls to the side
• rapid tire wear

When should wheel alignment be adjusted?

There are a number of repairs, after which wheel alignment is required:

• after installing a new ball joint
• when replacing the steering rack or steering tip
• after replacing and installing a new CV joint

To carry out wheel alignment adjustments, we recommend that you use only high-quality spare parts that you can find in the IXORA store. Qualified managers will definitely help you make the right choice and answer all your questions. Contact us, it’s profitable and convenient.

Manufacturer	Detail number*	Part name
CTR	CEKD16L
CTR	CEKD16R	Steering end for CHEVROLET LACCETTI
CTR	CEM14	Steering end for MITSUBISHI SPACE STAR
DELPHI		Steering rod for MERCEDES-BENZ 190
DELPHI		Right steering wheel end for OPEL, VAUXHALL
DELPHI		Tie rod for VW Passat
DELPHI		Steering rod for SEAT, VW
DELPHI		Tie rod end for BMW 3, Z3
DELPHI		Tie Rod End for PEUGEOT 306
DELPHI		Steering rod for VOLVO
DELPHI		Tie rod for CITROEN, PEUGEOT
DELPHI		Tie rod for FORD TRANSIT
DELPHI		Tie rod for VOLVO
DELPHI		Tie rod for FORD MONDEO
DELPHI		Tie rod FORD ESCORT, ORION, VERONA
DELPHI		Tie rod FORD COURIER, FIESTA, KA
DELPHI		Front tie rod end for OPEL, SAAB, VAUXHALL
DELPHI		Tie rod VOLVO 440, 460, 480
DELPHI