What to do if there is a decrease or absence of compression in the engine cylinders?

The problem surfaced a month ago. I came to the garage and started the engine as it should. I turned it off and started it again after 10 minutes, but the starter turned as if the spark plugs had been unscrewed. I unscrewed the spark plugs and measured the compression, it was somewhere from 0.3 to 0.7. although it was 8.5 in about all of them. I turned it around, walked around the car, back and forth, and then decided to measure the compression again and VOLYA everything fell into place 8.5! In general, that time the problem went away on its own.

Yesterday the same thing happened, only the problem does not go away on its own! Compression to the half-lames! In cylinder 1 the needle doesn't even budge! In the rest, it rocks the boat a little.

Help with advice! I assume that it’s rings, but it’s somehow not realistic for everyone at once! MYSTIC AND ONLY! I'm thinking of pouring oil or gasoline directly into the cylinder and maybe it will start?!

Compression inside the engine determines the overall condition of the engine, since at low levels it is difficult to even start the car. Reduced power, interruptions in operation, increased engine oil consumption, and fuel combustion are the main consequences of decreased air pressure in engine compartments. Loss of compression in all cylinders indicates serious problems with the power unit. In such cases, diagnostics should be carried out immediately, and, if necessary, repairs to the “heart of the car”, which gives life to the entire vehicle.

Reasons for decreased or lost compression

An aggressive driving style, as well as improper maintenance of the “iron horse” can lead to various malfunctions of its operation. The reasons for the decrease in pressure inside the cylinders are often caused by negligence towards your vehicle and can be the following:

• a dirty air filter makes it difficult to create a fuel-air mixture, which automatically reduces compression;
• constant overheating leads to scoring on the pistons and cylinders, and in worst cases the pistons can burn out;
• rupture of timing belts (gas distribution mechanism) often leads to valve deformation;
• errors when installing the camshaft according to marks during repair;
• malfunction of the gas distribution system;
• If there is excessive load on the engine during vehicle operation, increased wear of the piston rings occurs, and the cylinder head gasket (cylinder head) may also burn out. In addition, cylinder head cracks also lead to leaks and a decrease in pressure inside the engine cylinders;
• Incorrect valve adjustment leads to air supply disturbances and, as a result, a decrease in compression.

All these problems are accompanied by a loss of compression inside the power unit, both in one and in all cylinders.

Instructions on how to determine the reasons for the lack of compression and measure it

Hello! On a VAZ 2114 there was poor compression in 1 cylinder, but in the other three everything was normal. I removed the head, changed the valve in cylinder 1, but did not touch the remaining three. After assembling the engine, the car began to run as before, only the compression disappeared completely in the second cylinder, and in cylinders 1, 3, 4 everything was normal. What is the reason? (Peter)

Good afternoon, Peter. There can be many reasons why compression disappears. We will look at all of them below.

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Why does compression disappear?

Measuring the compression level using a device

1. If the engine is already quite worn out, then the valve in the second cylinder may also crack. In addition, the valve itself may not fit well when the motor is running, and this, in turn, causes leakage in the place where the element comes into contact with the “seat”.
2. If the so-called seat has collapsed, it helps reduce the pressure level.
3. Check whether you installed the cylinder head correctly after the last repair. It may have been installed incorrectly or it may have burned out, which is quite possible due to wear and tear. In addition, during installation, debris could get on the gasket (in particular, on its contact surface), or the gasket could burn out due to engine overheating. This will subsequently lead to cracks or deformation of the head.
4. Another reason is cylinder scuffing (c-ra), which usually appears after the internal combustion engine overheats.
5. Perhaps the entire cylinder-piston group has completely worn out.
6. The valve of the second cylinder may not close completely or does not close at all. Or there is not enough air entering it, but in this case you will also be able to hear a knock. In addition, the element could bend, but this is if your timing belt breaks while driving. It should also be noted that malfunctions in the functioning of this system can also lead to a decrease in pressure.
7. The inter-ring bridges of the pistons have become unusable.
8. The inlet element has failed. For this reason, pressure may disappear in one or several cylinders. In addition, a crack may appear in them, which is also a fairly common option.
9. The overall level of compression may be reduced as a result of carbon deposits on the rings.

One way or another, in any case, you will once again need to dismantle the cylinder head and gasket. It is likely that the problem lies precisely in the inability of the latter. In any case, we hope that our recommendations will help you solve the problem.

Video “How to check compression using the example of a Renault car”

We invite you to familiarize yourself in more detail with the procedure for checking the compression level.

avtozam.com

How to properly control pressure in engine compartments

To determine compression, a device is used, which is a pressure gauge with special adapters. Using adapters, this device is connected to the spark plug sockets of gasoline engines or the injector holes of diesel engines. In this case, it is necessary to follow some rules, observing a clear sequence of actions:

• It is important to make sure that the battery is charged and the starter is in good condition;
• Unscrew the candles and thoroughly clean their nests of debris;
• Then carefully connect all parts of the device to the engine through the spark plug holes or diesel injector holes.
• Start the engine, while recording the instrument readings. You should start the engine with the throttle valve open and also closed, comparing the results in the future. Check each cylinder in this way;
• Compare the results obtained with the necessary technical data for a specific vehicle. Based on these data, one can quite accurately draw conclusions about the condition of the timing belt, as well as the piston engine group.

What are the reasons for poor gear shifting?

Difficulty shifting gears can occur as a result of improper operation of the gearbox, or due to operation of the vehicle on bad roads. Problems with the gearbox sooner or later occur in used cars.

If you have difficulties when trying to switch to another gear, you cannot shift or it takes a lot of effort, then there is clearly a malfunction. Most often, car owners turn to a car service when they have difficulty engaging first or reverse gear. A fairly common problem on VAZ and Ford Focus cars.

Let's look at the faults that lead to difficult gear shifting:

• Clutch malfunction. In this situation, the gears will engage either poorly or not completely. A common occurrence in VAZ cars that have fur cables. the clutch is moving away from the mount.
• Problems in the drive of the switching mechanism. Broken traction leads to difficult engagement of 1st and reverse gears.
• The jet thrust is faulty.
• Wear of plastic parts in the box control drive.
• The slide is incorrectly positioned. A weighty element, incorrect adjustment leads to malfunctions.
• Bearing wear. This is a fairly rare occurrence; anyone can experience this, especially when you have a manual transmission. In such a situation, it is usually difficult to engage first gear.
• The box shaft is faulty. By itself, it is not subject to heavy loads, which could lead to wear. A factory defect may cause the entire unit to be replaced.
• Clutch failure. Often found among owners of cars with an automatic transmission. The malfunction is eliminated by replacing the clutches.
• Faulty synchronizers are the most common problem among gearbox breakdowns. They are made of brass, and this metal itself is quite soft. During use, it wears out and wears out. The breakdown is usually accompanied by a grinding noise when switching to another speed.

Some faults can be diagnosed and fixed independently, but failure of the bearings or shaft cannot be determined. For these purposes, you need special tools and equipment, as well as experience. In this situation, if you have problems shifting gears, it is best to go to a service station.

Does compression always indicate engine health?

Before we consider the signs and reasons why there is no compression in one or more cylinders, we will analyze whether this parameter affects the performance of the power unit. If the pressure in the lubrication system of a 406 or other engine is below normal, in practice this indicates wear of the internal combustion engine components. But it is not always the case. When mating the piston rings with the plane of the cylinders, it is the lubricating fluid that collects on the walls of the engine that plays an important role. Thanks to engine oil, the interface of the components is sealed.

When not all of the air-fuel mixture burns in the power unit, this leads to an increase in fuel consumption. If spark plugs fail, fuel will wash motor fluid from the walls of the engine, because gasoline is a good solvent. And if there is no lubricant in the system, there will be nothing to seal the combustion chamber with. Accordingly, because of this, air under pressure will begin to enter the crankcase of the power unit. This leads to the fact that in a 4-6- and 8-cylinder internal combustion engine, compression will drop sharply and disappear.

If its level is normal or higher than necessary, this will cause increased consumption of motor fluid. Due to increased compression, the rings wear out faster. And the gaps formed as a result of wear will begin to be sealed with lubricant, which is in abundance. This problem requires prompt repair. But in fact, compression does not show such a malfunction.

You will learn how to correctly perform the diagnostic procedure from the video published by the AssistanceTV channel.

What compression should the VAZ-2109 injector and carburetor have?

What is engine compression. How to check the compression of a VAZ 2109? Often, car owners are faced with vibration that unexpectedly occurs when driving at idle speed, and large fuel combustion. There are several reasons for this deficiency, for example, problems with spark plugs or malfunctions of the fuel system.

Poor engine compression can also lead to such consequences. If diagnostics of the fuel system shows that everything is in order, you need to check the compression in the cylinders.

Compression is the maximum pressure in the cylinder that occurs at the end of the compression stroke (at the moment the piston reaches top dead center). To measure compression there is a special device called a compression gauge (a pressure gauge with a hose and a fitting at the end).

What is engine compression. How to check the compression of a VAZ 2109?

Poor compression in the cylinders leads to the following consequences:

• fuel consumption increases;
• dynamics deteriorate (acceleration);
• the accelerator responds poorly to the pedal;
• poor “traction”;
• black exhaust appears.

Checking the compression of the VAZ 2109 engine with your own hands

1. Before measuring compression, you need to check the valve clearances and adjust them.
2. Warm up the engine to 70-80 degrees.
3. Turn off the engine, remove the spark plugs (to do this, use a spark plug wrench).
4. Disconnect the fuel hose and clamp it to prevent fuel from leaking.
5. Remove the central drive from the ignition coil.
6. Use a compression gauge installed in the spark plug socket to determine the indicators.
   Start checking from the first cylinder. Each cylinder must be checked separately.
7. At this time, the assistant must turn the starter so that the compression gauge can record the resulting pressure.
8. Record the device indicators.
   The minimum permissible compression is 10 kg/sq. cm, and the spread between the cylinders should not exceed 1 kg/sq. see. If your readings differ greatly from each other, we can conclude that there is wear on the compression rings, valves that do not fit well on the seats, or problems with the tightness of the cylinder head gasket.

If the cylinder compression is less than the figure indicated above or is different in each cylinder, a major overhaul of the engine is required.

Most likely, you will have to change the cylinder head gasket, grind in and adjust the valves, and install new piston rings. It is possible that the piston rings are stuck, then the engine will have to be decarbonized.

To narrow down the range of possible problems, you need to do a few simple tests with an air compressor.

1. Set the piston of the cylinder being tested to the top dead center position.
2. Tighten the handbrake, turning on speed 4-5.
3. Start the compressor and supply air under pressure to the cylinder.

Monitor the air flow

• If you hear a hissing sound in an adjacent cylinder, there is most likely damage to the gasket between the cylinders. To solve this problem, you need to replace the cylinder head gasket.
• To make sure that there are no breakdowns in the engine cooling system, you need to remove the radiator cap or expansion tank and make sure that the coolant level does not increase when air is pumped. A breakdown may be indicated by air bubbles or a change in the color of the coolant, or the appearance of an exhaust odor.
• If there is a hissing sound in the manifold or exhaust pipe area, it is most likely due to the intake or exhaust valve.

Source:

How to diagnose a VAZ 2108-21099 engine using a compressor

Only experienced specialists can visually clearly identify this or that engine problem; it is quite difficult, almost impossible, for an ordinary driver to do this. Of course, you can notice potential problems by the exhaust or sound, but this is only a small part of all possible malfunctions.

More accurate diagnostics are performed using serious instruments. This article will discuss engine diagnostics, which are more complex than visual, using simple, simple instruments.

Diagnosis of the VAZ 21099-2109-2108 engine using simple DIY tools

What is needed for diagnosis:

• a compression meter that measures compression in the cylinders;
• an oily rag that is used to determine the compression stroke of the engine. A tool made by combining a fitting for spark plug holes and a regular whistle will be convenient and effective;
• adapter for spark plug holes, which is used in the process of checking the tightness of the combustion chamber, compressor for inflating wheels.

Diagnostic procedure

The operating algorithm is as follows:

• It's better to start with compression. First, you need to warm up the engine to operating temperature, and then turn off the fuel supply. In this case, the hose on a carburetor engine is removed, compressed and pinched with something, or simply lowered into some container.
• For an injection engine, everything is much simpler - you just need to pull out the fuel pump fuse. Then you need to start the car (there should be some fuel left in the fuel rail) and wait until the engine stalls.
• After this, the ignition system is turned off, for which the central wire is removed from the distributor, and the sensor on the injector that monitors the position of the crankshaft is turned off.
• All debris that has accumulated there must be removed from the spark plug wells so that it does not get into the cylinders. After this, all the candles are unscrewed.
• Next, the compression gauge fitting is screwed in or inserted—it all depends on the model—after which the assistant begins to start the engine. The starter must rotate the engine until the pressure gauge needle stops in one position. Such measurements are carried out on each cylinder, and their results are recorded.

There is a special formula with which the ideal compression can be calculated for any engine. Compression is 1.2* compression ratio.

For example, the VAZ 21083 engine has a compression ratio of 9.8. Thus, its compression will be equal to 1.2 * 9.8 = 11.76.

This means that a compression of 11-12 atmospheres is quite normal for this engine. But each measurement has its own errors.

What factors may influence measurements?

• only a new or well-repaired car can have a compression of 12 atmospheres, for example, after an engine overhaul;
• a cold engine that has not reached operating temperature will have significantly lower compression;
• if the battery is weak or begins to “crumble”, then the engine will not turn so fast, so in this case the compression will be less;
• compression increases due to the combustion of oil in the cylinders - as a result of its combustion, the connection is sealed.
• Having recorded all the measurement data, it is necessary to analyze it. The spread of results for all cylinders should not exceed one atmosphere. For example, if in one cylinder the compression is 9 atmospheres, and in the other three – 11, then in this case you need to think about it. To more accurately determine the nature of the malfunction, it is necessary to carefully monitor the pressure gauge readings, or more precisely, how the pressure increases with each crankshaft revolution.

If at the first revolution there is low pressure (3-4 atm.), and with subsequent revolutions it increases, this indicates wear on the cylinders or problems with the rings. In this case, when about 10 cubes of engine oil are added to the cylinder, an increase in compression will be observed already with the first revolution.

When at the first revolution a compression of 5-8 atmospheres is observed, and with subsequent revolutions the picture practically does not change, this indicates possible valve deformation or a leaking cylinder head gasket

Important! A serviceable engine at the first revolution “produces” 6-8 atmospheres, and with subsequent revolutions it “pushes” up to 11-12 atmospheres.

After analyzing the overall results, we can draw the following conclusions:

• compression of 0-4 atmospheres indicates a probable burnout of the piston, valve or cylinder head gasket;
• compression 4-6 atm. usually indicates broken piston rings or partitions between these rings;
• if the compression in each cylinder is approximately the same and amounts to 8-10 atmospheres, then this indicates wear of the cylinder-piston group, so it is necessary to prepare for the upcoming engine overhaul;
• A new and run-in engine can have a compression of 12-12.5 atmospheres.

If a car with decent mileage produces results equal to or higher than normal, this indicates that oil may have gotten into the cylinders. The probable reason for this is wear of the cylinder-piston gear or valve guides.

Now it is necessary to compare the obtained data with the results of a visual inspection.

So, everything has been examined, an analysis has been carried out and the problematic cylinder has been found. But the overall picture still requires clarification. In this case, it is necessary to check the cylinder for leaks.

Leak test

You can check the tightness of the cylinder as follows:

• Use an oiled rag or the previously described device with a whistle to close the hole in the problem cylinder.
• It is also necessary to lift the car (it is enough to lift one drive wheel). Everything will be much simpler if there is a “crooked starter”.
• When the top gear is engaged, you need to turn the drive wheel or turn the engine using a crooked starter in neutral gear. It is necessary to rotate the crankshaft until the oily rag flies out or the whistle begins to whistle. Using this simple method, you can determine the compression stroke in the required cylinder.
• Next, the car is lowered, the handbrake and gear are engaged, after which the suspicious cylinder is inflated by a compressor (in extreme cases, air from the wheel can be used).

By the hiss of air you can get a more accurate picture:

• air escaping from the adjacent spark plug hole indicates a burnt-out cylinder head gasket;
• air escaping from the carburetor indicates a problem with the intake valve;
• A hissing sound in the muffler indicates a burnt out exhaust valve. A side effect of this malfunction is the engine “triggering” and smoking. This problem is the most common;
• Air coming out of the crankcase gas outlet indicates piston burnout or ring wear.

So, using the simple procedures described above, you can accurately determine whether this car is worth buying (if this was the purpose of the diagnosis), or find out whether your favorite car needs repairs.

Source:

Measuring compression in a VAZ 2109 engine

Compression in the cylinders of a VAZ 2109 engine is a very important indicator, on which not only power depends, but also the internal condition of the engine and its parts.

If the car engine is new and well run-in, then it is generally accepted that excellent compression will be 13 atmospheres.

Of course, you shouldn’t count on such indicators if your car’s mileage is already quite long and has exceeded 100,000 km, but it’s worth keeping in mind that a compression of at least 10 bar is considered the minimum acceptable.

To diagnose their VAZ 2109 engine, many people turn to specialized service stations for this procedure, although in fact this work can be done independently, having with you a special device called a compression meter.

I bought such a device for myself a few months ago, and now I measure compression on all my cars myself. The choice fell on a device from Jonnesway, since I have been using instruments from this company for quite some time and am very pleased with the quality.

Source: https://granta-service.ru/tyuning/kakaya-kompressiya-dolzhna-byt-na-vaz-2109-inzhektor-i-karbyurator.html

Signs of a drop or loss of pressure

Let's look at the symptoms that can be used to determine weak and low compression in all, two or the first cylinder. If your blood pressure is low or absent, the signs are:

1. Difficulty starting the power unit. In order to start it, the driver needs to turn the starter longer. And as a result of a complete loss of pressure, the engine cannot be started at all.
2. The engine began to function less stable. Due to the drop in compression, its speed at idle and when driving in gear will be unstable.
3. Increased fuel consumption. At first glance, identifying this symptom is problematic, but if you monitor this parameter, you can calculate it.
4. Problems appear in the functioning of the cylinders. When going uphill, there is a knocking sound from the hydraulic compensators (“fingers”). This is especially obvious when driving at low speeds.
5. In a diesel engine, the problem manifests itself as popping noises.
6. The pressure in the cooling system lines may increase. As a result, antifreeze will begin to squeeze out from under the sealing elements.
7. If there is poor compression in one or more cylinders and this is due to damage to the cylinder head gasket, then the tightness of the system as a whole is compromised. By opening the hood, you can diagnose this problem by the presence of exhaust gases that exit through the gap that appears. Such a malfunction leads to stuck piston rings, which ultimately increases fuel and oil consumption. In some vehicles, this symptom is complemented by an increase in the power of the power unit and the appearance of abundant smoke from the muffler.

Signs and causes of disappearance

There are actually quite a few signs and reasons why there is no compression in one, two or all cylinders at once. Therefore, for users of our resource, materials have been collected that can help determine a decrease in the pressure level in the system.

Signs

If a gasket burns out in the cylinder head, the tightness of the cylinder itself is immediately compromised. This can be seen if exhaust gases begin to escape through the resulting gap. At this moment, the rings become stuck, which entails increased consumption of motor fluid and gasoline. In addition, in some cases, the engine power may increase, and smoky exhaust will come out of the exhaust pipe.

Cylinder operation diagram

If your car has lost compression in all cylinders at the same time or in just one of them, then the signs may be as follows:

• the engine became much more difficult to start;
• the engine is unstable, both at idle and while driving in gear, at all speeds;
• you noticed that your “iron horse” began to consume much more fuel;
• problems also began with the cylinders;
• if your car is equipped with a diesel internal combustion engine, then while the engine is running you will hear frequent popping noises;
• The pressure in the cooling system pipes increases.

Causes

What could be the reasons? There are a lot of them, but we will look at them all:

How long will the engine last?

Low pressure is a problem that car enthusiasts often face. If the drop is insignificant, then the engine can be operated for a long time. But keep in mind that too little compression or its complete absence may be due to the strong heating of the unit.

Long-term operation of a car with an overheated internal combustion engine will eventually lead to its complete failure.

Detailed instructions for measuring pressure in engine cylinders are given below and filmed by the Made in Garage channel.

Motor Lada Priora (126 and 127): breakdowns and service life must be checked

The engine is the basis of any car - without it there is no movement and Drive! The engine on the Priora comes in 2 modifications: 21126 and 21127, the second is essentially a modified 126 engine, which has been installed on Lada Priora since 2013. after restyling the Lada Priora car model.

126 engines (16 valves) are high-torque after 1000 rpm, and up to 4000 - this is the maximum torque, after 4 thousand the torque decays. The 127 engine, due to the distributed air intake, pulls well from below, damping out at about the same rate as its brother. If the running-in was carried out properly, then the engine life will be close to 200 thousand km. Overhaul of the engine of a Priora car, like the entire AvtoVAZ range, is subject to the garage - there is nothing supernatural about it.

The price of spare parts is more expensive than tenths, but cheaper than foreign ones. Engine power of 98 and 106 hp allows you to feel confident on the road - well, certainly not a vegetable. I consider the main 2 disadvantages of the engine to be the unit: pump roller, timing belt. If one of these spare parts fails, the valve bends. 2 minus - camshaft plugs: when these rubber bands dry out at low temperatures, they are squeezed out along with the oil.

If you don’t see this in time, there will be trouble! The fact that hydraulic compensators knock when cold is considered the norm - you can close your eyes to this, there will be no harm.

In the vast majority of cases, Lada Priora cars are equipped with a 16-valve engine (the 8-valve engine was “inherited” from the “ten” and was not warmly received by car enthusiasts due to its sluggishness, but it has a huge advantage over the 16-valve engine - it does not bend valve).

The first 16 valve engine received number 126, the second – 127. The characteristics of the Priora engine No. 126 turned out to be so good and optimal that the car with this engine was sold most often. Repair of the Priora engine with 16 valves is not carried out so often, but you will have to look into it at least once every six months - in order to make sure with your own eyes that everything is in order with it. In addition, you need to keep an eye on the timing belt - if you miss this unit, you can get into big money. Read the article to the end, and we will tell you about these 2 units.

126 Priora engine - looks like this

Motor 126 and 127: working life, differences

These engines on Priora had a displacement of 1.6 liters (or 1596 cm3). Optimal for city sedans, the engine size of the Lada Priora gave a good combination of dynamics and consumption: along with very decent acceleration, fuel consumption does not exceed sky-high numbers. Both engines received good marks, because the car behaved perfectly in the city and on the highway.

In fact, the 126 Priora engine became the first sixteen-valve engine for this model, and the 127 is a modified version, “overclocked” by AvtoVAZ designers. In addition to the same engine displacement, they have other identical characteristics. The in-line type of arrangement of four cylinders provides a simplified design that can be repaired on your own.

The distributed multipoint injection system is involved in creating a good, rich fuel-air mixture (a lean mixture can lead to breakdowns). The cylinder diameter is 82 mm, the piston stroke is 75.6 mm, the compression ratio is 11. The “engines” fall under the Euro 4 standard, they are powered by gasoline with an octane rating of 95.

The 126 engine for the Priora received the following characteristics: 98 hp. (72 kW at 5600 rpm), acceleration to 100 km/h in 11.5 seconds (with manual transmission), city consumption 9.1 l - 100 km (manual transmission), maximum torque - 145 Nm.

The 127 engine for the Priora was upgraded to the following figures: 106 hp. (78 kW at 5800 rpm), acceleration to 100 km/h in 11.5 seconds (with manual transmission), city consumption 8.9 liters per 100 km (with manual transmission), maximum torque – 148 Nm.

The difference may not seem so noticeable, but this is a very small but strong step in design on the part of AvtoVAZ (this is where the change to sixteen-valve “engines” with a volume of 1.6 liters ended). For a car of the Lada Priora class, the engine power was sufficient.

In the same block it is necessary to say about the operating temperature. An absolutely normal operating temperature is considered to be between 90 and 95 degrees Celsius. Further, when the car is being pushed in a traffic jam, is basking in the sun, or for some other reason, but can still work - from 97 to 110 degrees. The engine is slow in places and wears out a lot, but you can still get to your destination. A temperature below 90 degrees is a direct sign indicating that the car has not yet warmed up, and it is better to wait in place until the arrow points to the coveted 80-90 mark.

Operating a car at temperatures above 110 degrees is dangerous because the service life of the engine is noticeably reduced - hot parts undergo very severe wear, overcoming the force of friction.

In general, the service life of the Lada Priora engine with a normal driving style and careful treatment is 200,000 km - after this mark the time comes when the “engine” requires major repairs. AvtoVAZ mentioned the timing belt separately as a recommendation, saying that it needs to be checked every 100,000 km (many car enthusiasts talk about the figure of 50,000 km).

All Lada engines have a problem, and it is related to the valves, which will be discussed further.

Are the valves bending?

When the timing belt breaks on a Priora, the valves will bend. That is why it was said above how often you need to check it for damage. Any crack or tear can be the start of a very fun adventure: when the belt breaks, the car will not move under its own power and will have to be rescued from the scene of the breakdown.



How much does engine 126 and 127 cost?

Engine 126 has catalog number 21126100026030, sells for about 107,000 rubles, engine 127, respectively, has catalog number 21127100026030, its price is slightly higher by 3-5 thousand rubles. The price on the secondary market will be significantly lower (up to 20-25 thousand rubles), but the savings will not pay off - a used “engine” can last no more than 1000 km, this is a real lottery.

How to find out what engine is in a Priora

You can find out by looking at the plate on the left glass of the rack, where the engine number is written on the edge. From it you can understand the 8-valve unit, or 16. You can also recognize the modification 21126 or 21127.

Signs of the need for internal combustion engine repair

The reasons why the operation of the engine is disrupted are arranged in a small list, starting with refusal to start and ending with floating idle speed (this problem was removed on the 127 “engine”). Not all breakdowns end in capital damage - sometimes it’s enough to add oil, sometimes it’s enough to adjust the ECU settings.

Compression reduction

A decrease in cylinder compression below 16 atmospheres is a bad sign. Such a high limit corresponds to a compression ratio of 11.

If the compression decreases (or vice versa increases), then the “engine” will have to be rebuilt.

Knocks in the engine

Engine knocks can come from several points. These could be hydraulic compressors, timing belt rollers or pins. The knocking noise could also be caused by low oil level. The answer to the question will be given by a thorough detailed inspection of all parts of the unit and checking the oil level.

Blue smoke from the exhaust pipe

The blue smoke that comes from the exhaust pipe appears when oil enters the combustion chamber. It can leak either from the valves or from under the piston. The result is the same: the oil is eaten up and blue smoke pours out of the chimney. Once the leak is located, half the problem will already be solved.

Troit motor

Sometimes in the cold the engine may stall - don’t be alarmed by this, because it may simply be one of the spark plugs that fails. In this case, we advise you to simply restart the engine and it will stop running.

How much does it cost to overhaul a Priora engine - average price

Self-repair of a Priora engine with 16 valves costs an average of 16-20 thousand rubles. The cost depends on the severity of the breakdown and may be lower or higher than this average range. Repairing a Priora engine can be entrusted to the wrong hands, but then you will have to pay for the work - sometimes the cost of repairs reaches as much as 40 thousand rubles.

This is an unreasonably inflated figure, because, as practice shows, you can rebuild the engine on a Priora, working at a moderate pace, in just three days - and three days of work is definitely not worth that kind of money. Don’t be afraid of not being able to cope - your Lada is easy to repair, and using the advice and “tutorials”, you will conquer even such a task that is impossible at first glance.

Source: https://priorik.ru/126-i-127-dvigatel-na-prioru-16-klapanov-resurs-priznaki-polomki/

Causes of compression loss

Now let's try to find out why the pressure in one or more cylinders is lost. The causes are divided into mechanical and non-mechanical. Let's look at them separately.

Non-mechanical damage

First, let's look at the non-mechanical reasons why compression in a car engine has disappeared. These include errors made during the repair of the power unit. If you yourself or at a service station set the valve timing incorrectly, the valves will be able to close, but not at the moment when required. During the compression stroke of the cylinder they will be slightly open. As a result, some air will begin to leave the system. And the displacement will not be enough for the valves to come into contact with the pistons, which will lead to their damage.

Sometimes the problem is associated with coking, as well as stuck piston rings. Such a malfunction will cause the valves to begin to stick into the grooves. Gases will pass through them easily due to the lack of a seal. With such a malfunction, the oil scraper rings function correctly, and the engine fluid cannot fill the gaps that appear in the system, since the lubricant will be washed off the walls by the remnants of the air-fuel mixture, which has not been burned.

Mechanical damage, wear

Damaged exhaust valve

If a 4- or 8-cylinder engine is running without compression, the reasons may be mechanical. Low pressure in the engine suddenly formed due to the fact that:

1. The exhaust valve has been damaged. Cracks appear on it due to natural wear and tear of the power unit. In addition, it may not fit well enough.
2. The valve seats themselves were destroyed. Weak compression is due to the presence of mechanical damage on them.
3. Worn or burned out cylinder head gasket. This usually occurs as a result of natural depreciation. Less commonly, the reason is that contamination gets on the plane of the sealing element. Gasket burnout can occur during long-term operation of a vehicle with an overheated engine. This, in turn, will lead to the formation of cracks in the cylinder head, and the head or block itself may become deformed.
4. Mechanical faults also include cylinder scuffing. This occurs as a result of overheating.
5. Wear or damage to the cylinder-piston group.
6. Breakage or complete destruction of the inter-ring bridges of the piston elements.
7. Intake valve failure.
8. Formation of cracks and other defects directly on the pistons or cylinders.
9. The appearance of carbon deposits on rings and seals, which contributes to a drop in compression.
10. Damage and further breakage of the timing belt or chain. The timing belt is a consumable item, so it must be replaced periodically. Due to a break, the valves of the power unit may bend.

What to do if the engine has no compression or low compression

It is quite obvious that a decrease in compression indicates the need to repair the power unit, which involves disassembling and troubleshooting the internal combustion engine. Only after these procedures can you get an idea of ​​the condition of the CPG and timing belt, as well as other elements and components of the engine.

However, it also happens that the cause of a decrease in compression can be eliminated without disassembling the engine. We are talking about removing coke, carbon deposits and deposits. This solution allows you to clean the combustion chamber, restore mobility to the piston rings, remove carbon deposits from the valves and ensure their tight fit.

To more accurately determine how serious the problem is, without disassembling the internal combustion engine, you first need to pour 7-8 “cubes” of engine oil into the problem cylinders. Then the compression needs to be measured again.

If adding oil does not change the situation, then valve related problems are likely. If the compression increases after adding oil, then you should look for the problem in the wear of the CPG elements. So, in this case, the rings could have stuck, and decoking the piston rings in some cases can correct the situation.

Let us immediately note that this method will not necessarily help, but it is worth a try, especially since the owner will not require significant financial investments.

• In short, to decarbonize the engine, you need to purchase a special cleaning fluid.
• Next, you need to unscrew the spark plugs and pour 30-40 grams into each spark plug hole.
• Then the spark plugs are not screwed in (you can cover the holes with a clean rag), and the car itself should be left in the garage for 10-12 hours.
• After the specified time, you will need to crank the engine with the starter with the spark plugs removed. Next, the spark plugs are cleaned and reinstalled.

Please note that after pouring the decarbonizer, you must not immediately screw in the spark plugs and try to start the engine! In this case, residual liquid in the combustion chamber can cause water hammer.

After the engine has started, the engine needs to warm up a little, after which you will need to go on the highway. Then the car is accelerated to 110-130 km/h, after which you need to drive 25-30 km at high speeds.

We also recommend reading the article about why the engine has high compression. From this article you will learn about the main reasons for increased compression in engine cylinders, why this phenomenon also negatively affects the operation of the internal combustion engine, like a decrease in compression, and also what to do in this case.

Upon completion, compression measurements must be repeated. If nothing has changed, then bracing the rings did not help or the problem lies in severely worn parts. In this case, the engine only needs to be repaired.

We also add that some car owners seek to avoid internal combustion engine repairs and actively use various additives to restore compression. It is important to understand that in practice such solutions can help in some cases, but they are simply not capable of removing burrs and “smoothing out” other defects.

In fact, such compositions are also decarbonizing agents, but the price may differ significantly from more affordable analogues. Some other additives for restoring engine compression can further complicate the inevitable repair of the power unit if the composition is positioned as a metal revitalizer, that is, it tends to form a so-called protective and restoring layer on worn surfaces.

Checking the compression level

A sharp drop in pressure will ultimately lead to serious problems with the engine. If there is no compression in one cylinder, and the reasons are unknown, then diagnostics must be performed.

Rules for measuring quantities

Let's consider the nuances that should be taken into account when checking:

1. Before diagnostics, the power unit must be spun up to maximum speed using a starter device. To do this, it is necessary to provide all conditions, reducing the likelihood of energy loss to a minimum.
2. It is necessary to open the engine hood and disconnect all high-voltage wires from the spark plugs. The devices themselves are unscrewed and dismantled. This prevents rotational resistance from developing.
3. When diagnosing, the power unit should be warmed up; the test is performed on a warm engine.
4. Before the process, the fuel supply is turned off to prevent the engine fluid from being washed off from the walls of the engine.
5. It is necessary to fully charge the battery in order to spin the engine crankshaft as much as possible.

Detailed instructions for self-diagnosis of the parameter were published by the Auto_Repair channel.

How to check the level?

To find out about small or weak compression on spark plugs in the first, second or other cylinder of the engine, you must adhere to the following rules:

• the power unit must be spun up by the starter to extremely high speeds, for this it is necessary to reduce the likelihood of energy loss;
• the procedure should not be carried out on a cold engine in order to ensure maximum coupling at temperatures closest to operating temperatures;
• You must first turn off and unscrew the spark plugs from the cylinders to prevent the formation of resistance to rotation;
• you need to turn off the fuel supply so that the engine fluid is not washed off the cylinder walls;
• It is necessary to charge the battery as much as possible to effectively spin the crankshaft.

Using a compression gauge

To check the compression level using a compression meter:

1. You need to warm up the car to operating temperature
2. Relieve the pressure level in the fuel rail. Afterwards, you need to start the power unit again.
3. The next stage of diagnosis, which will allow us to understand the cause of the drop in compression, will be the removal of the tips located on the spark plugs.
4. At the next stage, you need to check whether the compression has dropped in all four cylinders of the engine.

Table: measurement results

Oil check

The oil test is carried out using 15-20 grams of lubricant, which is poured into an incorrectly operating cylinder.

Then you need to check:

• thermal clearances of valves on each cylinder;
• motor;
• lubricant.

Then the engine is assembled and started, and the cooling system expansion tank is diagnosed.

Video: checking compression without using a compression gauge

The Secret GARAGE channel presented a video showing a way to check the pressure in the engine cylinders without using compression equipment.

Using a compression gauge

To perform the test, you will need an appropriate device. A compression gauge is a simple pressure gauge equipped with extensions, as well as adapters designed to connect to different spark plugs. The types of such devices differ depending on the type of power unit - gasoline or diesel . This is due to the fact that the latter has a higher compression level.

1. Open the hood of the car, disconnect the wires from the spark plugs and unscrew them with a wrench. Remove devices.
2. Prepare the device for diagnostics. Connect an extension cord and adapters of appropriate sizes to it, install them in the spark plug sockets.
3. After installation, sit in the driver's seat and turn the starter device. On a diesel car, when diagnosing compression, it is necessary to remove the injectors.
4. Perform a check on each engine cylinder. The obtained indicators must be compared with those indicated by the vehicle manufacturer. They are usually noted in the service manual.

Video “What is the difference between compression and compression ratio?”

The main differences between these concepts are shown in the video (the material was filmed and published on Avto-Blogger channels).

Greetings. Guys, I'm in trouble, help me. The bottom line is this, the hydraulics were knocking, I bought new ones and changed them, the compression in the 4th cylinder was gone, in the rest it was 10. Before replacement, the compression was 14 everywhere. The piston is with grooves, the timing belt is set to the marks!! I took it apart five times...everything is fine. I reassembled it again, in the first cylinder the compression of 10 in 3 was gone, completely gone! I don’t understand what the hell this is.

Well, in short, this uncle allows him to take a car on weekends for personal use.

by Adminrive · Published 04/20/2015

Congratulations to all hockey fans

by Adminrive Published 05/09/2015

Oil check

Diagnostics can be performed using motor fluid. But for this you will still need a compression gauge:

1. Open the hood and disconnect the high voltage wires from the spark plugs.
2. Unscrew them from their seats. Pour 30-50 grams of motor oil into the sockets where they are installed.
3. Carry out a pressure diagnostic with the device. If the operating parameter has increased, and there is no difference in performance between the cylinders, then repair the seals or rings. They could have coked up. You can replace them yourself. In the case of rings, you will have to remove and disassemble the block head.

Where does the compression go?

Air under pressure can break through in several directions at once - through the pistons with piston rings, or through the cylinder head - through the intake or exhaust valves.

Non-mechanical damage

After repairing an engine by incompetent craftsmen, it happens that the valve timing is set incorrectly, and the valves seem to close, but not when they should - during the compression stroke the valves remain slightly open - this may be enough for air to escape, but the displacement is not enough, so that the valves come into contact with the piston and bend.

Another example is coking and ring sticking. In this case, the compression valves lie in the grooves and gases easily pass through them, because there is no seal. In this case, usually the oil scraper rings work, so the oil does not seal the resulting cracks. This is a similar example to when oil is washed off the cylinder walls by unburned fuel, but here the oil is simply removed by oil scraper rings.

Mechanical damage, wear

In case of mechanical damage, valves are more likely to suffer - they can burn, bend, fall out, the valve seat can burn out - in general, there will be no necessary mating of parts, and, accordingly, gases will break through.

The valve can bend for various reasons - the same belt will break, and the valves will meet the piston in an unequal battle. The result of this battle is obvious, so change the belt on time.

Level up on your own

Now we’ll tell you what to do to increase blood pressure. In garage conditions, it can be increased due to the formation of soot and deposits on the cylinders. All other faults can be resolved by dismantling the cylinder head and replacing damaged components. When removing the cylinder head, it will need to be bored, so it is better to entrust this process to specialists. How to increase the compression level:

1. Prepare kerosene and alcohol. It is necessary to mix 25 g of each substance in a one to one ratio. One cylinder of the power unit will require 50 g of the resulting mixture. If you need to increase the pressure in several at once, then multiply 50 g by the number of elements.
2. Start the vehicle engine. Let it warm up to operating temperature.
3. Pour about 50 g of a mixture of kerosene and alcohol into the cylinders whose compression needs to be increased. The car should sit like this for about ten hours.
4. After the time has passed, add about 20-30 grams of motor fluid and start the power unit. He needs to work for 20 minutes. With minor deposits on the engine walls, carbon deposits will be removed.

How to increase compression in cylinders yourself?

If the compression is below the normalized value, then it can be increased in several ways:

1. If the valves are incorrectly adjusted in 2 or other cylinders, then adjusting them will solve the problem of low compression. If the thermal clearances are not set to normal and the motor does not work, you will have to change the valves and grind them in.
2. A damaged cylinder head gasket must be replaced.
3. If the problem is the appearance of defects on the block head as a result of overheating, then the easiest way to increase compression is by trimming the surface of the unit. Serious defects in the body of the device can only be eliminated by replacing it.

What will you need?

To carry out decoking you will need:

• alcohol;
• kerosene;
• gloves;
• spark plug key.

Algorithm of actions

Guide to increasing compression level:

1. At the first stage, pure alcohol and kerosene are mixed in a 1:1 ratio. 50 grams of the resulting composition is poured into each engine cylinder.
2. The engine is started, the motor must warm up to operating temperature.
3. Then the high-voltage wires are disconnected and the spark plugs are unscrewed using a special wrench. A mixture of alcohol and kerosene is poured into each cylinder.
4. After adding the composition, the car must sit for at least ten hours.
5. Then approximately 20 grams of oil is poured into each cylinder and the engine is started. The engine must run for at least 20 minutes. If the deposit on the walls was not critical, then most of it will be removed.

Video: review of compression enhancement products

The video from the “Motoresurs” channel provides an overview of fluids designed to increase the level of compression in engine cylinders.

Is the motor acting up? Possibly due to lack of compression in the engine. We have found a solution for self-diagnosis, go ahead!

Compression in an internal combustion engine (ICE) is an increase in air pressure in the cylinder during the compression stroke , that is, when the piston moves up to top dead center (TDC). If there is no compression in the cylinders or it is close to a critical value, many problems arise that make the operation of the power unit difficult, and sometimes make it impossible. Loss of power, excessive consumption of fuel and oil, difficult starting, misfiring - these are symptoms that directly indicate depressurization of one or more cylinders. In the article we will tell you how to increase the service life of the engine, when and how to carry out diagnostics.