Over time, car parts wear out, not only the chassis, but also the engine. Why is a cylinder compression test required? For example, you are buying a used car, and in order to find out what condition the engine is in, it is better to play it safe and check the compression so that you don’t have to do a major overhaul after a couple of months. I bought my 10 when it was 5 years old; by that time the mileage was no longer low (about 90,000). When inspecting the car, I had a specialist with me who checked the compression in the cylinders.

Now let's take a look at how this is done. I’ll warn you right away that it’s better to check the pressure together, so ask someone to help you.

Work progress

To carry out the work we will need

• compression gauge
• spark plug wrench

for 8 valve

for 16 valve

This is where you just need an assistant. He must sit in the car and with the gas pedal fully depressed (full opening throttle valve) turn the starter (start the car) for 5-10 seconds. We record the readings of the device and check the pressure in the remaining cylinders in the same way.

Normal compression of a VAZ 2110 engine must be at least 1.0 MPa (10 bar) in each cylinder, the difference in performance between cylinders must not exceed 0.1 MPa (1.0 bar).

At the time of purchasing the car, my compression was 12 bar, which is very good indicator, now, I really don’t know how long the compression will show, but there seem to be no problems with the engine)) I hope the article was useful to you, thank you!

Over time, car parts wear out, not only the chassis, but also the engine. Why is a cylinder compression test required? For example, you are buying a used car, and in order to find out what condition the engine is in, it is better to play it safe and check the compression so that you don’t have to do a major overhaul after a couple of months. I bought my 10 when it was 5 years old; by that time the mileage was no longer low (about 90,000). When inspecting the car, I had a specialist with me who checked the compression in the cylinders.

If you notice that the engine does not pull, and along with this, fuel and oil consumption has increased, then you should perform engine diagnostics. You can determine the causes of engine problems without disassembling them by measuring the compression in the engine cylinders. Engine compression is the pressure in the cylinders at the end of the compression stroke. It is measured in kg/cm2, bar, MPa or atmospheres. When the VAZ compression is high, then fewer gases will break into the engine crankcase and, therefore, more gases will useful work, and this will have a positive impact on engine power. Thus, compression in the engine affects throttle response, engine stability, gasoline and oil consumption. Low engine compression will lead to a drop in engine power, reduced maximum speed vehicle, deterioration of acceleration dynamics, as well as an increase in the amount of consumed fuel and oil.

Now let's take a look at how this is done. I’ll warn you right away that it’s better to check the pressure together, so ask someone to help you.

VAZ engine compression

The standard compression indicator of the VAZ 2110 can be calculated using the formula: Compression (kgf/cm2) = compression ratio * X coefficient The compression ratio is in technical specifications engines, and it is different for each engine model. The X coefficient depends on the type of engine, and is equal to 1.2..1.3 for four-stroke engines With spark ignition; For example, compression of VAZ 2112 = 10.5 * 1.2 = 12.6. Now let's figure out how to measure engine compression: Work progress To carry out the work we will need: ✔ a compression gauge ✔ a spark plug wrench

1. First of all, you need to warm up your car to operating temperature and turn off the ignition 2. Then you need to relieve the pressure in fuel system. To do this, you need to remove the pump fuse and start the engine so that the remaining fuel in the system is used up. When the engine stalls, you can proceed to the next step 3. Disconnect the wire from the ignition module.

For 8 valve

for 16 valve

4. Remove from all candles high voltage wires and turn it inside out spark plug wrench all 4 candles. 5. Next, install the compression gauge in spark plug hole one of the cylinders.

for 8 valve

for 16 valve

This is where you just need an assistant. He must sit in the car and, with the gas pedal fully depressed (full throttle opening), turn the starter (start the car) for 5-10 seconds. We record the readings of the device and check the pressure in the remaining cylinders in the same way.

The normal compression of a VAZ 2110 engine should be at least 1.0 MPa (10 bar) in each cylinder, the difference in values ​​between the cylinders should not exceed 0.1 MPa (1.0 bar).

At the time of buying the car, my compression was 12 bar, which is a very good indicator, now, I really don’t know how much the compression will show, but there seem to be no problems with the engine)) I hope the article was useful to you, thank you!

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If over time you feel like your engine was more dynamic when you first started using it, the loss of power may be due to mechanical wear. The most common causes are high wear between the pistons and cylinders, worn piston rings, leaking or burnt valves, and a damaged head gasket or spark plug. At the end of the compression stroke, high compression pressure is created, which then during combustion air-fuel mixture increases like an avalanche. For pistons and piston rings cylinder walls, valves, valve seats, valve train gaskets as well as the cylinder head gasket this means high thermal and mechanical stress. As a rule, engines with reduced power already signal their technical condition. Symptoms include erratic behavior during cold starts or uneven engine operation, increased oil and fuel consumption, a plume of white or of blue color, elevated temperature coolant, poor exhaust gas performance and reduced engine power. To get a clear picture it is necessary at every second visit service center check compression. IN equally this also applies to diesel engines.

Control values compression

The compression values ​​for your vehicle vary slightly depending on the compression ratio. Presented in table. 4.2 guideline values ​​are valid for engines in perfect technical condition. When analyzing compression, greater importance is given not to the absolute highest values, but to the same values ​​in all cylinders. Deviations up to a maximum of 2 bar are allowed. If deviations exceed the permissible value, it is necessary to find out the reason for this deviation. As a first step, your specialist will advise you to take a pressure loss measurement.

Older engines create less compression

In older engines, compression is significantly reduced, and this is a normal phenomenon associated with normal wear and tear engine. Therefore there is no particular cause for concern, it depends less on the absolute highest indicator pressure, and more from the same values ​​in all cylinders. Only when the measured values ​​have reached the limit acceptable values, you need to think about the upcoming engine repair or replacing it with another one. If the difference in values ​​is more than 3 bar, practice indicates following reasons:

– wear of pistons or piston rings;

– jamming of worn piston rings in the piston grooves, caused by the deposition of combustion products;

– damage to the working surfaces of the cylinders as a result of slight jamming of the pistons or jamming of the piston rings;

– residues of combustion products and oil in the form of deposits on valve mechanism or on the working surfaces of valve seats;

– cracked valves;

– burnout of valves due to insufficient valve clearance or thermal overload.

You can measure compression yourself. First of all, for this you need an assistant who turns the starter crankshaft, and a device for measuring pressure. In well-equipped auto repair shops, a compression tester is part of the basic equipment. First, remove all spark plugs (in diesel engine- fuel injectors) from the cylinder head and ensure that the valve clearance is correctly adjusted. During the test, the assistant must fully press the clutch and accelerator pedals; you use the device to check the compression in each cylinder. Since diesel engines draw in the same amount of air at all times, there is no need to press the accelerator pedal. Start measuring with the first cylinder and then sequentially measure in all other cylinders. Count the number of revolutions crankshaft before creation maximum pressure, this amount will be the criterion for subsequent cylinders: the faster the compression is created, the “healthier” your engine is. In a “healthy” engine, compression should be created after 6–8 revolutions of the crankshaft.

The basis for a reliable measurement is a functioning starter and a fully charged accumulator battery

Despite the fact that this is an elementary truth, we still remind you once again that the basis for measurement is a starter with good traction force and a fully charged battery. If the crankshaft rotates very slowly, compression in the cylinder also occurs slowly - measuring compression loses its meaning. If you get large deviations in the measurement results, perform a pressure reduction test. Handling the device for measuring compression reduction requires some experience, so we recommend that you leave the test for measuring compression reduction to a specialist.

You can find out the reason for the decrease in pressure as follows.

· If compression is low, through the spark plug hole (in a diesel engine - into the injection nozzle hole), inject a little motor oil, then check again. The oil improves the seal between the mating surfaces of the pistons and cylinder walls.

· If the compression has increased slightly, the leak is occurring through the valves or the cylinder head gasket. Leakage through valves can be caused by burnt-out valve seats and/or valve lips, as well as deformed or cracked valve stems.

· If after the introduction of oil the compression increases, then we can make a clear conclusion that the piston rings are worn out.

Compression measurement

SEQUENCE OF WORK

1. Before measurement, warm up the engine to operating temperature. This creates optimal clearances between all moving parts.

2. Turn off the ignition (terminal “15”), remove the tips from the spark plugs and remove all spark plugs.

3. Tighten parking brake, place the gear shift lever in neutral position, press the clutch and accelerator pedals.

4. Firmly insert the rubber cone plug of the compression tester into the spark plug hole (in a diesel engine, into the spark plug hole). fuel injector). If necessary, use a suitable adapter device (

The pressure created in the engine cylinders is otherwise called compression. If its level in the cylinder is too low, a large volume is occupied by the fuel-air mixture, which has a low concentration, which leads to slow ignition.
At the same time, heat transfer increases and the engine overheats. If the compression level is very high, rapid combustion occurs fuel-air mixture, due to the high concentration, a detonation or explosion of the mixture occurs.
At this time, the engine experiences increased pressure, which has a destructive effect on its parts. There are situations when the compression in the cylinders on a VAZ 2110 is different.
In this case, ignition occurs faster in one cylinder, slower in the other, and the engine begins to operate unevenly. An imbalance is created in the operation of the pistons and shafts, which has a negative effect on their condition.

How to control compression in the cylinders of a VAZ 2110

Each method helps to more accurately determine node defects.Compression is most often measured with the throttles in the carburetor closed and open.
When the valve is fully open after measuring compression, the following defects can be detected:

• Presence of burrs or serious damage on the surface of the cylinder.
• No burnouts or valve deformations.
• Rings stuck or coked in the piston grooves.
• Broken or burnt pistons.

With the throttle closed, after measuring the compression, the following is determined:

• Is there a stuck valve? If the design has a hydraulic tappet, the presence of defects in the camshaft cam profile is determined.
• Seat valve fit.

The compression of the cylinders of a VAZ 2110, a car without a hydraulic compensator (see), is measured with the dampers open.

Compression measurement

In order to avoid negative consequences, from the compression deviation in the cylinders, it needs to be measured. To carry out DIY work, a device called a compression meter is used.
Its price is small, relative to the funds that will be spent on engine repairs when a cylinder needs to be replaced in a VAZ 2110.
So:

• When choosing a device, you need to pay attention to the limit switch. It connects to the engine and can be rubber or threaded.

Tip: Preference should be given to an end cap with a thread. It is more convenient to work with it and you can do it without outside help.

• The engine is warming up.
• Everything is unscrewed and removed.

Tip: It is better to measure compression when the engine is warm, with a well-charged battery so that it provides rated power to the starter.

• The wires are disconnected from the ignition coils.
• The fuel pump turns off (see). At mechanical device You can disconnect the hoses supplying fuel or shut off its supply.
  At electric fuel pump the fuse is removed or the relay is turned off to stop the power supply.
• A compression gauge is connected to one of the cylinders, as shown in the photo.

• The starter is turned on, which cranks the engine crankshaft until the highest pressure is set. The crankshaft rotation speed should be between 200 rpm and 350 rpm.

Advice: Special attention you need to pay attention to the position of the throttle valve, it should be completely open.

• The maximum reading of the device will correspond to the compression level in the cylinder.
• This is how compression is measured in the cylinders of a VAZ 21102, one by one in each cylinder. Details of the work can be seen in the video.
• The instructions indicate that in different cylinders the pressure should not differ by more than 0.1 MPa and its nominal value should be below 1.0 MPa.
• If on a VAZ 2110 there is no compression in one cylinder or it is low, this may indicate a loose fit in the valve seats, damage to the gasket, burning or breakage of the piston rings.
• To find out the reasons, you need to fill the cylinder in which the compression is low with approximately 20 cm2 of engine oil, and then measure the compression.

If the compression meter readings increase, it is most likely faulty. Maintaining compression values ​​indicates a loose fit of the valve plates to the seats or damage to the cylinder head gasket.

Tip: You can find out the cause of insufficient compression by applying pressure to the cylinder. compressed air. In this case, the piston must be installed in top dead compression stroke point.
To do this, remove the tip from the compression gauge and connect the compressor hose to it. The tip is inserted into the spark plug hole and air is supplied to the cylinder under a pressure of 0.3 MPa.
At this time, the crankshaft should not turn, it is fixed hand brake. For leaks intake valve indicates leakage through throttle assembly air, and exhaust - the air exits through the muffler.
Damage to the gasket is indicated by air escaping through the neck to expansion tank or into an adjacent cylinder, which is indicated by a characteristic hissing sound.

Compression is very important indicator for diagnosing engine parts without disassembling it. Based on the difference in values ​​found in different cylinders and its average, you can quite accurately determine how worn out the connecting rod and piston group of the engine is, and identify breakdowns in this group and parts in the valve mechanism.

Many VAZ-2110 owners wonder why their cars have different compression? Typically, compression is applied when the piston moves away from lowest point to the top. In this case, a certain pressure is created in the cylinder. Good compression can only occur if all gaskets, pistons, rings or valves are in in good condition. It is because of these elements that the air in the system is compressed.

Normal compression on a VAZ-2110

Typically, compression is checked using a special device. It is recommended to do this regularly.

This helps determine the degree of wear of the motor and rings, as well as the piston itself. The normal pressure in the cylinder on a VAZ-2110 with 8 valves should be from 10 to 12 atmospheres .

Normal compression in the cylinder.

It is also worth noting that sometimes the pressure in different cylinders may differ . If this 0.5-0.7 atmospheres , then this phenomenon is normal and should not cause concern.

Abnormal compression

This happens when the cylinder has much more or less atmosphere than the others.

Such an engine will not be able to operate normally. He needs to mandatory carry out repairs.

Causes

Burnout of the gasket between the block and the head is a fairly common defect.

There can be many reasons why there may be a difference in compression. Experts highlight the main ones. This:

1. The head and block gaskets are burnt out. It just needs to be changed.
2. The head is not tightened. The gasket may burn out here.
3. The rings don't hold. The reason here is the wear of the rings or their breakage. If the pressure drops in one cylinder, this often indicates a broken ring. This will require piston repair.
4. Coked rings. They will need to be cleaned.
5. Block wear. Happens rarely.
6. Motor overheating.
7. The piston is broken or burnt out. There is no compression at all.
8. Valves not adjusted.

Repair

As can be seen from the above, there are many reasons for different compression in the cylinders. In this case, it is not always possible to carry out repairs yourself, especially if you do not have the skills. In this case, it is recommended to contact specialists at a service station.

Traditional methods of increasing compression

It is noted that the methods described below cannot be a 100% guarantee that compression in the cylinders will increase.

• Buy quality liquid to clean the valves and pour it into the oil.
• Pour this liquid into the cylinders overnight.

conclusions

Knowing these points, you should not worry about the difference in compression in different cylinders on a VAZ-2110, if it is small. When the norm exceeds the permissible values, repairs will be required.