How to equalize compression in the cylinders of the VAZ 2110. Different compression in the cylinders

Over time, auto parts wear out and not only the chassis, but also the engine. Why is a compression test required in the cylinders? For example, you buy a used car, and in order to find out what condition the engine is in, it’s 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 took my top ten when she was 5 years old, by that time the mileage was no longer small (about 90,000). When inspecting the car with me was a specialist who checked the compression in the cylinders.

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

Work progress

To carry out the work, we need

• compressometer
• candle key

for 8 valve

for 16 valves

This is where you need a helper. He should 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 in the same way check the pressure in the remaining cylinders.

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

Compression is the pressure in the engine cylinders that is created at the end of the compression stroke. If the compression is too high, the concentration of the air-fuel mixture will be high, which will cause rapid ignition and explosions. As a result, the engine will begin to collapse.

Low compression reduces the power of the motor, the dynamics drops, it is not possible to develop maximum speed. Plus, fuel and oil consumption is noticeably increasing.

At low pressure (compression), the air-fuel mixture ignites slowly, causing the engine to heat up. Destructive consequences are inevitable if the problem is not corrected.

Causes of the malfunction

There are a number of reasons why the required level of compression may fall below the established norms. Therefore, before checking the pressure and carrying out repairs, you should understand the possible causes of the problem.

• Cylinder block gasket burnt out;
• Burnt pistons or valves;
• The cylinder-piston group has worn out;
• Valve seats collapsed;
• A crack has formed in the exhaust valve disc.

The manufacturer specifies the normal compression level and compression ratio for each engine. At the same time, these characteristics are confused, considering them one of the same. The compression ratio is the ratio of the total volume of the cylinder to the volume of the combustion chamber.

To calculate the optimal compression ratio for the engine, use the formula:

Compression = Compression ratio * K-factor.

In the case of gasoline engines, the coefficient is 1.2, while for diesel versions it is 1.8.

Why check

Measurements are carried out with the throttle valve open and closed. Each test option provides its own results and data on the condition of the engine.

The open damper test determines:

• Problems and damage on the surfaces of the cylinders;
• Deformation, burnout of valves;
• Sticking or coking of piston rings.

If you check the compression with the damper closed, you can find out:

• Are the valves stuck?
• Is there a tight fit to the valve seat;
• In the presence of a hydraulic pusher, the presence of defects in the camshaft cam profile is determined.

Ways

There are two main ways in which you can check the compression readings in the engine.

Examination

Now you can proceed directly to the test.

1. Warm up the engine, reaching the operating temperature, then turn off the ignition.
2. Turn off the fuel pump. If this is a mechanical pump, the pipes are disconnected and the fuel supply is blocked. In the case of an electric fuel pump, simply turn off the fuel supply relay and remove the fuse.
3. Relieve the pressure that has inside the fuel system.
4. Start the engine. So the engine will be able to use up all the fuel that is left in the system. Wait for the engine to come to a complete stop.
5. Now we continue to measure the compression.
6. Disable the ignition module.
7. Disconnect the spark plugs from the high-voltage ones, then use a special spark plug wrench to unscrew them from the sockets.
8. Insert a measuring instrument into the spark plug socket. On each cylinder, that is, when the device is connected to each hole, measurements are taken separately.
9. Invite an assistant. His task is to sit in the driver's seat and squeeze the gas pedal to open the throttle.
10. At the same time, the engine starts for 5-10 seconds.
11. You are currently taking readings from the meter.
12. By a similar method, measurements should be taken on each cylinder, resetting the readings of the previous one on the device. Write down the received data.

For VAZ 2110 engines, the normal compression is 10 bar or 1.0 MPa on any cylinder. A difference between indicators up to 1 bar or 0.1 MPa is allowed, that is, normal data is 11-11-11-11 or 10-11-11-10 and similar test results. If you deviate from them, you should look for the causes of the problem.

What affects the error

Measurements do not always give the most accurate result, since they are influenced by certain factors. As a result, we get an error.

Factors that cause inaccurate compression readings may include:

• Not fully open throttle. That's why it's important to depress the gas pedal all the way;
• Dirty air filter;
• Small clearance between valves. This results in a reduction in compression;
• Motor temperature. The data on a cold engine will be less than on a hot one;
• Cylinder head gasket that is damaged or burned out;
• The presence of fuel in the combustion chamber. Because of this, the readings will be less than the real ones. Therefore, it is important to expel all the fuel at the preparation stage;
• Lack of proper tightness of the check valve of the pressure gauge or compression gauge. Use high-quality, serviceable measuring instruments;
• Low engine speed.

You can also check compression on a cold engine. Then the readings will be halved compared to the norm, and the normal deviation is no longer 1, but 0.5 bar.

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

How to control compression in the VAZ 2110 cylinders

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

• The presence of scoring or serious damage to the surface of the cylinder.
• No burnouts or deformation of the valves.
• Hanging or coking in the grooves of the piston rings.
• Piston breakage or burnout.

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

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

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

Compression measurement

In order to avoid negative consequences, from the deviation of compression in the cylinders, it must be measured. For do-it-yourself work, a device called a compression gauge is used.
Its price is small, relative to the funds that will be spent on engine repairs when the cylinder needs to be replaced in the 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 a threaded limit switch. It is more convenient to work with him and you can do without outside help.

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

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

• The wires are disconnected from the ignition coils.
• The fuel pump is turned off (see). With a mechanical device, you can disconnect the hoses supplying fuel or shut off its supply.
  With an electric fuel pump, the fuse is removed or the relay is turned off to cut off 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 speed should be between 200 rpm and 350 rpm.

Tip: Particular attention should be paid to the throttle position, it should be completely open.

• The maximum reading of the device will correspond to the level of compression in the cylinder.
• This is how compression is measured in the cylinders of the VAZ 21102, in turn in each cylinder. Details of the work can be seen in the video.
• The instruction indicates 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 there is no compression in one cylinder on the VAZ 2110 or it is low, this may indicate a loose fit in the valve seats, gasket damage, burning or broken piston rings.
• To find out the reasons, you need to fill in the cylinder in which the compression is lowered, approximately 20 cm2 of engine oil, and then measure the compression.

With an increase in the readings of the compression gauge, it is most likely faulty. Preservation of 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 supplying compressed air to the cylinder. In this case, the piston must be at top dead center on the compression stroke.
To do this, the tip is removed from the compression gauge, and the compressor hose is attached to it. The tip is inserted into the spark plug hole and air is supplied under a pressure of 0.3 MPa into the cylinder.
At this time, the crankshaft should not turn, it is fixed with a hand brake. Leakage in the intake valve is indicated by air leakage through the throttle assembly, and exhaust valve - air exits through the muffler.
Damage to the gasket is indicated by air escaping through the neck on the expansion tank or into the adjacent cylinder, which is indicated by a characteristic hiss.

Compression is a very important indicator for diagnosing engine parts without disassembling it. By the difference in the values ​​​​that are found in different cylinders, and by its average indicator, it is possible to accurately determine how much the connecting rod and piston group of the engine has worn out, to determine the breakdowns in this group and parts in the valve mechanism.

The simplest and most accessible way for every driver to diagnose an engine is to check the compression in the cylinders.

Performing a compression test

We turn off the fuel supply, turn out the candles and measure the compression, both with the throttle open and closed. Of course you need an assistant. We get a bleak result - different compression in .

There can be any number of reasons for this: starting from the quality of the fuel and the operation of the fuel system, and ending (in the worst case) with a malfunction of the pistons, valves and the cylinders themselves. Do not forget to add here the defects in the seals.

Immediately, an unpleasant question is approaching like a formidable cloud - what, is it really necessary to do a major overhaul of the engine? The answer is unequivocal - no.

There are compression gauge readings, you need to put them into practice

In the event that low compression is visible in one cylinder and at the same time the engine idling is unstable, then there is a high probability of wear on the camshaft cam that controls the exhaust valve.

If the compression is different according to the scheme: low in two adjacent cylinders, then, most likely, the gasket between them burned out.

And finally, after you added a little engine oil to each cylinder and repeated the compression test, the readings went up - the piston rings were worn out.

Methods for eliminating low engine compression

As we have already said, there are a lot of reasons that there is a different compression in the cylinders. And, if you follow the "smart" books, then you need an autopsy, which, as you know, will show the reason.

But just one thought that a heap of problems will fall on you is terrifying. And the replacement of rings, the replacement of "caps", crankshaft oil seals. And if the gap between the piston and the cylinder is broken, then the boring of the block cannot be avoided. No, don't worry about it just yet.

Therefore, the first possible reason for the formation of low compression in the cylinder, experts recommend considering the occurrence of the rings. This is when they get too coked and practically stick to the piston. If the option described below does not eliminate the problem of different compression in the cylinders, then radical methods will be needed.

Folk way to eliminate the occurrence of rings and increase compression

This method is not a guarantee that the compression meter readings will change. But, it is actually effective if different compression in the cylinders was formed precisely because of the occurrence of the rings. At a minimum, your conscience will be clear, and then you will exclude this item from the diagnosis.

• We purchase high-quality liquid for cleaning valves. The instructions for it should indicate that it is added to engine oil.
• Tonight, we unscrew all the candles and pour 50-70 ml into cylinders. this liquid with a "pear" or syringe.
• In the morning, after 12 hours, scroll the engine, then clean the candles and adjust the gaps, and only then screw them into place.
• When starting the engine, do not be alarmed by the quality and quantity of smoke from the exhaust system.
• Drive onto the road to pass sections at higher speeds. That is, the task is to give the engine maximum load. Therefore, think in advance where you will do it. Consider the condition of the road surface, weather conditions, traffic intensity. Ideally, this is done on a country road.
• Important! The previous point must be fulfilled without fail, otherwise the coking products that have come off overnight will fall under the valve and then the cylinder head disassembly cannot be avoided.
• After running at a speed of 100-120 km / h in a section of 10-20 km. re-measure the compression in the cylinders.

If in one of the “pots” the pressure is significantly lower than in the others (for example, everywhere 11.5, and in the only 6.0 atmosphere), this indicates a difference in compression. Naturally, this negatively affects the operation of the power unit. Often, a drop in compression can be observed in several “goshkas”. However, in this case, we can safely say that the engine needs urgent overhaul. There can be many reasons for the drop in compression; to eliminate it, the cylinder head must be dismantled. Here are the main reasons:
1. Broken (burned out) cylinder head gasket. One of the most common causes is “treated” by replacing this element.
2. Cylinder head not tightened enough. Actually, the aforementioned reason follows from this, the gasket begins to let pressure through and breaks through it over time.
3. Skip the rings. A similar phenomenon is relevant if the o-rings are badly worn or broken. If the pressure dipped in one "" pot "", the rings are guaranteed to be broken. In this case, an overhaul of the engine is required.
4. Coking. The rings are covered with coke due to the use of low-quality engine oil or high mileage. The oil burns out and the rings stick in one place, unable to walk in their grooves. Only one side is ground, respectively, the engine wears out faster. Coking is indicated by a drop in compression in all cylinders.
5. Wear of the walls of the cylinder block. The phenomenon is rare, occurs most often due to the use of low-quality materials by the manufacturer.
6. Overheating of the internal combustion engine. If the engine overheats, the rings and the walls of the block begin to leak pressure, and with it the oil. Partially can be determined by the blue smoke from the exhaust pipe.
7. Piston burnout. If the piston is broken, the compression in the cylinders will be virtually zero. It can burn both from above and from the side. Often, the pistons break when the timing belt breaks, when, due to a violation of the valve timing, they meet with the valves.
8. Valves. Compression may drop due to improper adjustment, burnout or breakage when the timing belt breaks.

Recently I was asked a question on my blog - why can there be different compression in the engine cylinders? The question, I’ll tell you the truth, is an interesting one, I personally asked myself a very long time ago when I was sorting out the engine, now it’s less and less because I drive more or less fresh cars. However, for those who have a run of 150 - 200,000 kilometers, it is dedicated ...

So why does this happen - when the pressure in one is much less than in the others? There may be several reasons for this, all from my experience, but almost always you need to remove the block head:

1) Broken gasket . This happens very often when it breaks the gasket between the block and the head of the block - we just change it.

2) Head not tightened . This is a continuation of the first reason - if the head is not tightened correctly, the gasket can also leak pressure.

These are the simplest reasons, but they are the most common - for example, this often happened on my new purchased VAZs, in particular on the VAZ 2114 and from a friend on the VAZ 2110. So, first of all, we climb there, on the new "our brands" - the problem it will be in this by 80%. More difficult problems follow.

1) Missing o-rings . This happens from wear, or from the fact that they broke. However, if your pressure has dropped in one of the cylinders, then most likely it is broken. The repair is complicated, you need to disassemble the block itself to pull out the pistons.

2) Rings coked . I decided to take it to a separate point - from low-quality engine oil, the rings can coke.

It's just that the oil burns at the points of contact and seals the rings in one place - although this is not correct, the rings do not go along their grooves, but only one side is machined, which leads to rapid wear - though this way the pressure will drop in all 4 cylinders. Because the oil lubricates all 4 pieces.

3) Block wall wear . This is rare - but it happens, that is, the ring has nothing to do with it, but it is the walls that they rub against that suffer. Most likely, this is a low-quality material.

4) . When overheated, the tightness of the rings and block walls is lost, they begin to pass both pressure and engine oil. An indirect sign is at work.

5) Burned out - the piston itself broke . In such cases, compression may simply drop to "zero".

Sometimes the piston itself burns out, it can be like a small “burnout” will say from the side, as well as a very large one - for example, in the middle. It also happens that the piston breaks, for example, from meeting with the valve when the timing belt breaks - again we lose the atmosphere.

6) valve . There are a lot of reasons. This is the wrong setting. And the burnout of the valve, it happens - one burns, so the compression will vary in just one cylinder. It can also break if the timing breaks.

These are the main reasons why the values ​​will differ in exactly one pot out of all four.

Repair

As I wrote above, it is really difficult to make repairs yourself. Unless, of course, your gasket has been pierced - it’s really possible to repair here, but again, it’s not so easy. How to replace a small video.

Diagnostics is carried out with the head of the block removed - here it is already 100% possible to determine the malfunction. You are unlikely to do it yourself, contact the specialists at the service station, or understanding people.