Effective decarbonization. Do-it-yourself decarbonization of oil scraper rings. Causes and symptoms

Imagine the situation: you decide to check the compression on the engine of your car, which is already several years old, and you are surprised to learn that it is 30-40 percent below normal. Usually in such cases it is advised to overhaul the power unit. This procedure is quite expensive: but is it worth the rush? Is it really impossible to do without a major overhaul? It is likely that engine decarbonization will help you: what it is, why you should do it and how, you can find out below.

Why is engine coking dangerous?

We are talking about carbon deposits that form on the walls of the combustion chamber, piston heads, valves and other parts inside the engine. The formation of deposits is associated with incomplete combustion of the fuel-air mixture, to which are added tiny particles of substances from the exhaust gases. Here are some reasons for the formation of soot:

• constant engine operation at low speeds or idling (for example, regularly standing in traffic jams);
• driving on low-quality fuel;
• using oil not recommended by the car manufacturer;
• independent attempts to “improve” the engine, associated with the introduction of inappropriate elements into it.

As the parts of the cylinder-piston group (CPG) wear out, the walls of the cylinder head, pistons, valve surfaces, grooves for rings and spark plug electrodes begin to become coated due to oil penetration into the combustion chamber. When the amount of coke reaches a critical level, all sorts of channels and holes begin to clog. All this results in a number of problems:

• the thickness of the cylinder walls becomes larger, i.e., heat dissipation worsens and the engine begins to overheat more often;
• coke getting under the valve prevents it from closing tightly, as a result of which the part may burn out;
• the gap between the cylinder walls and the piston rings decreases, which causes the latter to lie in their grooves and reduce compression;
• pressure surges in the chamber provoke, which quickly brings a major overhaul of the engine;
• oil consumption increases.

If you do not take measures to decarbonize the engine, a major overhaul of the engine is inevitable. It is clear that sooner or later it will still have to be carried out for a used car. However, a timely procedure will delay this unpleasant moment by 20-30, and in some cases even 50 thousand kilometers.

Mechanical decarbonization

This involves disassembling the engine and cleaning its elements from carbon deposits. This method is used when the engine is almost “killed” and chemical cleaning methods, even the most “nuclear” ones, did not give the desired result. Before you start doing mechanical decarbonization, weigh your strengths and capabilities (availability of tools, devices): the engine must not only be disassembled, but then also reassembled! The algorithm of actions is simple in theory:

1. Disassemble power unit. It is not necessary to dismantle it from the car: you can remove the cylinder head (cylinder head) and the oil pan to gain access to the necessary components.
2. Dismantle and pull out the pistons, disassemble the cylinder head, pull out the valves.
3. Clean the parts, avoiding the appearance of scratches and scratches on their surfaces, which, after being put in place, can become a kind of “abrasive” that attracts carbon deposits.
4. After removing the coke, wipe the parts with a clean rag and gasoline and reassemble the engine.
5. Fill with fresh oil and install a new filter.
6. Start the engine, warm it up and drive 50-60 kilometers without excessive load.

Chemical decarbonization

Compared to mechanical, it is carried out more often, because it is distinguished by the relative simplicity of the procedure (even an inexperienced motorist can handle it) and lower costs. There are a couple of chemical decarbonization methods.

Soft (partial) method

It consists of adding a special additive to the fuel or oil. It is used when the engine is slightly coked and helps to get rid of not too much carbon deposits on the oil scraper rings and other parts of the CPG. The result will be noticeable no earlier than after 50 km. Advantages of the soft method:

• low financial costs;
• ease of use;
• relatively quick achievement of the effect with low coking of the engine.

Among the negative aspects, it is worth noting that it is useless in the presence of serious deposits and the need for mileage after the procedure. The soft method is more likely to be a preventative measure. Below are some of the most popular remedies.

EDIAL

There are several types of this product: for cars with mileage up to 60 thousand km and more than 100 thousand km. The first of them is used mainly for prevention. Add to the oil filler neck (1 bottle per 5 liters of lubricant). After filling, let the engine idle for 10-15 minutes. Next - operation in normal mode, no need to change the oil, but spark plugs are recommended.

B.G.

The product number 105 is more of a preventative and is added to the oil. BG109 is stronger and is used to decarbonize motors with slight carbon deposits. BG110 is interesting: the manufacturer recommends pouring it into fresh, just changed oil.

GZox Injection & carb cleaner

Japanese auto chemicals intended, among other things, for cleaning carburetors and injectors. Well suited for soft decoking of CPGs. The product contains ethyl glycol and petroleum solvent. These substances in “union” form an oily film on the surface of the parts. GZox Injection & carb cleaner is recommended to be used as a preventative composition every 10 thousand km. A 300 ml can is enough for most cars with a cylinder volume of 1.5-1.8 liters. In application, it resembles the method of hard decarbonization (described below), but it acts more gently. Changing the oil is not necessary but is advisable: you can use a flushing compound and it’s worth

Hard method

Complete decarbonization helps to more effectively clean CPG parts from carbon deposits and is used for cars with high mileage. The procedure is common for any product; it is described below, then the most popular auto chemical products in this regard are described. Hard decoking (you can first flush the lubrication system with an appropriate composition):

1. Warm up the engine and measure the compression in the cylinders to compare the effectiveness of the product “before” and “after”.
2. Place the car on a jack (one wheel - front if front-wheel drive, rear if rear-wheel drive).
3. Turn them out if you are not going to change them.
4. Engage 5th speed and turn the wheel until the pistons are in the middle position. You can check this by using a long screwdriver inserted through the spark plug hole into the cylinder.
5. Take a syringe or tube (if the product is not an aerosol) and use it to fill the cylinders in the amount recommended by the car chemical manufacturer.
6. For an hour, periodically turn the crankshaft (turn the wheel) 1 revolution approximately every 15 minutes, adding auto chemicals.
7. Screw the spark plugs back in.
8. Leave the car with the product poured in for 4-15 hours (according to the instructions).

When the holding time is over, unscrew the spark plugs again and use a syringe to pump out the contaminated mixture from the cylinders. Blow them out with compressed air. Change the oil and filter: it won't hurt either. If your car is a diesel, the procedure is the same, only instead of spark plugs you need to unscrew the injectors. Now about the means for hard decarbonization.

Kerosene with acetone

The traditional “old-fashioned” method, quite effective and least expensive. Helps to free CPG and timing parts not only from carbon deposits, but also from more persistent varnish deposits. To decarbonize the engine, 1 cylinder requires 150 ml of a mixture prepared in the following proportion: 50 parts of acetone, the same amount of kerosene and 25 parts of motor oil. The mixture must be poured into a warm engine. After completing the procedure, you need to change the oil and filter.

Laurel ML202

Promoted domestic brand. Although in reality the effect of its use is comparable to good old kerosene and acetone. If express cleaning is required, 45 ml of liquid is poured into the cylinders and left for 40-60 minutes. In more advanced cases, it will take 12 hours (but no more than a day).

VeryLube (XADO)

An aerosol that decokes and removes varnish deposits from rings and pistons. This decarbonizer is not particularly effective; it is recommended to use it when the compression discrepancy between the cylinders is not too large. After finishing the work, starting the engine for the first time is difficult.

Mitsubishi Shumma Engine Conditioner

Strong, effective remedy, but also expensive (about 1500 rubles). Moreover, in different regions It is not so easy to buy it in Russia. The cleaner is a chemically active foam. It is introduced into the cylinders through a tube, kept for 4-5 hours. It does not show aggression towards valve stem seals. One can is enough for a 1.5 liter engine.

Greenol Reanimator professional

Domestic aggressive agent. Restores the performance of the rings, partially removes deposits in the oil drainage channels. The product contains strong solvents, distillates, and various additives. For the best effect, pour 50-80 ml into each cylinder and add the composition as it evaporates. Swells after use valve stem seals, but they regain their shape in about a night. There will be a chemical smell in the cabin for a couple of days. If your pan is painted from the inside, you should not use this product: everything will corrode and the particles will clog the filter mesh.

Black smoke from the exhaust pipe, increased fuel consumption, tripping - all these are symptoms of the appearance of carbon deposits on the surface of the pistons or, in other words, coking of the engine. Do-it-yourself engine decarbonization involves a series of actions aimed at cleaning the cylinder-piston group, compression and oil scraper rings from carbon deposits.

Causes of soot formation

Solid coke deposits appear not only due to improper operation, but also due to the specifics of engine operation.

The main factors of engine coking:

• Penetration lubricants into the combustion chamber;
• Incomplete combustion of the fuel mixture.

Also, the causes of carbon deposits in the engine can be:

• Using motor oil not specified by the vehicle manufacturer;
• Operate the machine only in city mode;
• Frequent engine operation idle speed;
• Frequent engine overheating;
• Incorrect commissioning after a long period of vehicle inactivity.

Not quality fuel or failure of the oil seals causes the formation of deposits to accelerate. Oil enters the combustion chamber through cracks in the oil scraper rings and becomes coked under the influence of high temperature, which leads to decompression.

Carbon formation zones

Coke deposits accumulate in the grooves located under the compression and oil scraper rings. This leads to insufficiently tight fit of the rings to the cylinder walls and poor quality oil removal. Continued use of oil scraper rings without repair leads to friction, overheating of parts and burnouts in the piston.

Signs of ring wear:

• Oil on exhaust pipe;
• A sharp increase in oil consumption;
• Blue smoke from the chimney when starting to move;
• Dirty spark plugs.

Analyze whether your car has one or more signs and, having given a positive answer, check the functionality of the oil scraper rings.

Why is engine decarbonization necessary?

Many car owners believe that buying a modern car will save them from having to get rid of carbon deposits in the engine. But is this really so? Even high-tech piston systems may need engine decarbonization.

Without paying attention to the symptoms of ring coking, you can cause irreparable harm to the entire piston complex. The appearance of soot leads to the following consequences:

• An increase in the thickness of the cylinder walls and a deterioration in heat dissipation;
• Poor valve fit and the possibility of burning out;
• Reducing the gap between the piston rings and the valve walls, which in turn leads to a decrease in compression and ring sticking;
• Increased oil consumption due to impaired mobility piston rings.

Carrying out decarbonization yourself will help either solve problems with the engine or determine that a service call and major repairs are necessary.

What does decarbonization give:

• Restoring engine performance;
• Economical oil and fuel consumption;
• Increased engine dynamics;
• Reducing the amount of harmful impurities in exhaust gases.

A decoking procedure can eliminate symptoms of decompression and loss of power. There are several methods for decoking an engine. Each of them is based on the pouring of special chemicals; only the methods of carrying out the procedure and the chemicals used differ.

Please note that engines of cars with high mileage and a significant degree of wear may deteriorate in their performance after decarbonization. Due to severe wear of parts, coke deposits act as a seal, and their destruction leads to a decrease in compression.

Decarbonization using chemicals

Currently, many decarbonizing products have appeared, each of which has its own characteristics in terms of chemical composition and method of use:

• LAVR ML-202 from a domestic manufacturer. It is popular due to its relatively low cost and good efficiency. Can be used for preventive purposes;
• SURM is another domestic product. When using it, there is no need to change the oil after the procedure;
• Edial is an easy-to-use product that is poured into the fuel tank before refueling;
• Xado Anti-Coke, complete with Atomic Conditioner, shows excellent results, but is quite expensive.

But no matter how much the chemicals cost, overhauling the engine at a car service center will still cost more.

There are two ways to fill chemicals: with hard decoking, pouring is done into the engine cylinder, with soft decoking, pouring into fuel or oil.

Hard decarbonization

To carry out hard decoking, the car must be horizontal. Before carrying out the procedure, it is advisable to find out what the engine compression is at the moment to compare with the indicators after cleaning.

Step-by-step instruction:

1. Warm up the engine to operating temperature;
2. Unscrew the spark plugs or injectors on the diesel engine;
3. Raise the drive wheels with a jack;
4. Set the pistons to the middle position by slowly turning the crankshaft in high gear;
5. Using a syringe through the spark plug opening, pour the selected chemical into the cylinders. The quantity depends on the volume of the cylinder;
6. Put the spark plugs back and leave the chemical in the cylinders for the time specified by the manufacturer;
7. Rotate the crankshaft for optimal distribution of the drug every 5 minutes for the first 30 minutes;
8. Unscrew the spark plugs and remove the liquid using a syringe;
9. Reset the negative terminal of the battery;
10. Turn the starter in neutral for 10 seconds to avoid water hammer;
11. Reinstall the spark plugs;
12. Connect power;
13. Start the engine;
14. Let the engine idle for about half an hour.

Depending on the chemical used, the oil and oil filter may need to be changed.

If the rings are heavily coked, it is better to pour the chemical through the hole in the injectors, having previously unscrewed them. The time for exposure to chemicals varies, depends on the chemical composition, and in some cases can range from several days to a week. The stronger the coking, the longer it takes.

Immediately after decoking the engine, the car may have difficulty starting. As a rule, the first start will also be accompanied by a pungent smell of exhaust gases.

Attention! Harsh cleaning uses highly toxic substances. The procedure for removing coke deposits should take place in a room with good ventilation.

Decarbonization with a mixture of acetone and kerosene

Proportions for decoking: three parts acetone to one part kerosene. The total amount is calculated based on engine volume - 300 grams per four-cylinder engine.

Step-by-step instruction:

1. Prepare a mixture of the desired proportions and volume;
2. Unscrew the spark plugs on a slightly warm engine;
3. Pour the mixture into the cylinders;
4. Put the candles back;
5. Leave the product to act on carbon deposits for a period of 9 to 12 hours;
6. Unscrew the spark plugs;
7. Turn off the power;
8. Remove excess fluid by rotating the starter;
9. Start the engine.

If necessary, repeat the procedure to increase the effect. Change the oil and oil filter. Please note that after cleaning, oil is washed out, which can lead to wear on the piston rings.

High engine temperatures can cause the mixture to boil.

Soft decarbonization

A good way to do engine decarbonization with your own hands, without having specific skills and experience.

• Pouring into oil

If the time when you need to change the oil coincides with the desire to clean the rings, then add a special chemical to it. After adding chemicals to the oil, you can drive 100-200 km, and then change it. It is impossible to do complete cleaning in this way, but it is quite possible to remove deposits from oil scraper rings. Due to the thinner consistency of the oil, avoid driving at high speeds.

• Filling with fuel

Pour a suitable decarbonizer, such as Edial, into the fuel tank. Getting into the combustion chamber, it destroys the structure of the soot, and the particles, burning, come out along with the exhaust gases.

Preventing carbon deposits

In order to avoid problems associated with engine coking, adhere to the following recommendations:

• Do not let the car sit idle for a long time;
• Try not to let the car for a long time operate at low speeds;
• Warm up the engine in winter period;
• Change the oil in a timely manner;
• Use decoking additives.

By properly operating your car and periodically carrying out gentle decarbonization, you can protect your car engine from breakdown.

During engine operation, heavy carbon deposits may form on the cylinder rings. This happens for two main reasons: the use of low-quality fuel or oil getting into the combustion chamber. In small amounts, deposits have virtually no effect on the performance of the engine. Subsequently, drivers may encounter the following problems:

• reduction in engine power;
• reduction of compression;
• the appearance of detonation;
• problems with starting;
• the gas pedal has become less sensitive;
• increased engine oil consumption;
• the appearance of bluish smoke from the exhaust pipe;
• oil deposits on spark plugs.

All these signs indicate the need to clean the rings. In the worst situations, rings and even pistons can become deformed due to detonation. Decarbonizing piston rings with your own hands is not very difficult. On the market you can find dozens of special products for removing deposits.

Causes of coking

In rare cases, low-quality fuel becomes a source of excessive coking. The content of a high percentage of impurities leads to incomplete combustion of the mixture, gradually forming a layer of soot. If you use high-quality fuel, then there is only one reason - oil getting into the cylinders. It (unlike the fuel-air mixture) does not burn completely, which leads to coking.

Why oil gets into the cylinders is a separate issue that car owners urgently need to solve. Decarbonization is the same preventive measure as brushing your teeth. If you do not want to do it regularly, then you need to eliminate the cause of the soot. Oil leakage can occur for the following reasons:

• Natural wear and tear or damage. The lower oil scraper ring will not be able to remove excess oil from the cylinder mirror, which is why more and more composition will gradually accumulate in the grooves. It will burn, leaving a black residue.
• Worn or damaged valve stem seals, which are necessary to remove excess.
• Small scratches or deformations on the cylinder bore, in which oil can accumulate.
• Using low quality or old oil. Over time, the composition loses its fluidity characteristics, which makes it difficult to remove residues from the mirror.

After the operation, you can see for yourself whether decarbonizing the piston rings helps. Compression should be restored, detonation should disappear, the car will be more “spirited and alert to the explosion.” Next, it is necessary to consider the existing decarbonization methods and how they are performed.

Methods for decoking piston rings

The driver can perform decarbonization in one of two ways: with or without disassembling the engine. The latter option involves the use of various means. Next we will talk about the advantages and disadvantages of each of these methods.

Disassembly of the unit and complete cleaning

This method is the most effective and time-consuming method. As a rule, it is used only in extreme cases when no other remedy has helped. The advantages are obvious: it is possible to remove all deposits with one hundred percent probability, thoroughly cleaning every square centimeter of the surface. Also, during disassembly, you can evaluate the condition of the piston rings, and, if necessary, naturally, replace them.

The problem is the complexity of the operation. Not all drivers are able to disassemble and then correctly reassemble the engine. You will have to contact specialized technical centers and pay for such services. To avoid this, do not allow coking to reach a critical level. When the first signs appear, use various special means.

Decarbonization with water

An affordable method without any investment. To do this, you will need to prepare distilled water in a bottle, a dropper and a hose. Some motorists also recommend diluting 100 milliliters of hydrogen peroxide with 5 liters of water to improve the effect. It is better to perform flushing using this method before changing the oil, since some of the carbon deposits will end up in the old oil.

1. Make a hole in the bottle cap and then insert one end of the dropper (with the cylinder).
2. We connect the other end to the hole in the intake manifold, and it is necessary to adjust the flow through a special regulator on the dropper. Achieve 2-3 drops per second.
3. Start the engine. Bring it up to 2000 rpm.
4. “Pump” in this way from 1.5 to 3 liters of solution.

Thick white smoke may come out of the exhaust pipe. This means that the carbon deposits have begun to gradually flake off and be removed. The method requires some skill. By supplying too much water, you risk causing the motor to experience water hammer, which will completely disable it. The disadvantage of this method is also its duration, because decarbonization with water can take several hours.

Decarbonization with kerosene

When the coke layer is large enough, you can try using kerosene. Drivers should mix kerosene and acetone in equal proportions. Additionally, you can add oil so that the mixture lasts longer in the cylinder. This procedure must be carried out before changing the engine oil (similar to the previous method).

Follow these instructions:

1. Remove all spark plugs.
2. Place the cylinders in one line. Pour 100 milliliters of the mixture into each of them.
3. Put the candles back in place. Leave the car for 8+ hours.
4. Unscrew the spark plugs and place a rag on the wells.
5. Run the starter so that the remaining solution comes out.
6. Install the candles. Take a ride by car. As a rule, in the first 15 kilometers, carbon decarbonization and carbon removal occurs through the exhaust.

Only after this can you completely change the oil. The presented methods require virtually no investment. They allow you to decarbonize the piston rings without disassembling the engine.

The methods described above have one general rule - the oil should be changed immediately after their implementation. If you don’t want to do this, you can use a number of additives for gasoline or diesel. The main function of such additives is to remove combustion products with a special chemical composition. It enters the cylinder along with the fuel, reducing carbon deposits and removing what is already there.

The advantages of additives include:

• ease of use (just pour in the additive);
• no need to dismantle spark plugs or change oil;
• a protective film appears on the cylinders.

The technique is only suitable for removing small amounts of carbon deposits (in more severe situations, additives will be powerless). The disadvantage is low performance. You will feel the effect only after several hundred or thousand kilometers.

TOP 5 best decarbonizers

If money is not an issue, then it is better to buy specialized product for decoking of piston rings. On the market you can find products costing from several hundred to thousands of rubles. It is impossible to definitively determine the best product for decarbonizing piston rings, so you will have to use personal trials to find the most suitable one for your case. Next, 5 popular and in-demand products will be presented.

Mitsubishi Shumma Engine Conditioner

First-class product made in Japan. Many craftsmen and mechanics prefer it. It is a petroleum based solvent. Contains ethylene glycol and mono-ethyl ether. Shumma is a composition from the category of hard decarbonizers. It is developed for engines with direct injection, but can also be used in other types of internal combustion engines. Input into the cylinders is carried out through a tube. Next, you need to keep the composition for 3 to 5 hours. An important advantage is that Shumma Engine Conditioner is non-aggressive to valve stem seals. The downside is that it is one of the most expensive products.

GZox Injection

Another Japanese product. It is actively used for cleaning carburetors and injectors, while it decarbonizes the rings. GZox contains petroleum solvent and ethylene glycol. It has a gentle effect on the piston, while additionally creating a protective film. It is also allowed to use the product as a preventive measure every 10 thousand kilometers. It removes carbon deposits perfectly, but it cannot decarbonize oil channels. GZox Injection is a product in the mid-price category, so it is easier to find on the shelves of auto stores than Shumma.

Kangaroo ICC300

Designed in Korea. It is not a decarbonizer, although it copes with this task perfectly. It is recommended to use it to remove carbon deposits after the car has been parked for a long time. ICC300 is water-based and is characterized by high solubility in oil. The composition includes 3-methyl-3-methoxybutanol, lauryl demethylamine oxide, 2-butoxyethanol. It can only be used on a warm engine. To achieve the best result, the product should act on the cylinders for at least 12 hours. The affordable price makes this composition extremely popular. There is only one drawback - a weak effect at room temperatures.

VeryLube (XADO)

The product is made in the form of an aerosol. According to customer reviews, it is ineffective. It can only be used with low coking levels. They will not be able to clean the oil channels, but the product can flush the engine oil system. Under this name you can find several products from the mid-range and budget categories. Contains dispersing components, aliphatic hydrocarbons. Safe for rubber components, but the manufacturer cautions that VeryLube may damage paintwork.

Greenol Reanimator

A Russian product that can cope with decarbonization of any complexity. This effect is achieved through the use of powerful solvents, so the product does not meet international environmental safety standards. The composition is capable of destroying valve stem seals. The advantages include a large bottle of as much as 450 milliliters and high efficiency when cleaning individual parts (valves or cylinders). Use this liquid for decarbonizing piston rings with caution due to its high aggressiveness.

How to protect your car from carbon deposits

In order not to buy a piston ring decarbonizer and not to carry out cleaning procedures, we recommend following a few tips:

• use high-quality fuel and oil;
• do not let the car sit idle for a long time;
• change the oil and oil filter promptly;
• do not drive with damaged piston parts;
• in winter, try to warm up the engine.

Before using any special product, carefully study its composition and effect. If possible, consult with mechanics.

Conclusion

Carbon deposits on cylinders are a typical problem that can be easily fixed in your garage. Drivers can choose among several methods (clean everything themselves or buy special compounds). The market offers a wide range in different price categories. Buy products only from trusted stores so as not to come across dangerous handicraft products. High-quality decarbonization will reduce oil consumption and add power to the vehicle.

October 6, 2017

Information about cleaning the engine from carbon deposits (otherwise known as decoking) will be useful to those car enthusiasts who constantly operate one car for a long time and try to maintain it themselves. This procedure is, rather, preventive in nature, although in some cases it allows you to revive the power unit and extend the mileage before major repairs by 5–20 thousand km. How to decarbonize an engine with your own hands and what means are used for this, read in this publication.

Where does carbon deposits come from and where does it accumulate?

The cleaning procedure is not a panacea and does not always help, and sometimes gives the exact opposite effect. To use the technique correctly and on time, you need to understand the reason for the formation of deposits and the consequences of this phenomenon.

Cylinder piston (CPG) and valve group of the engine internal combustion works in difficult conditions - at high pressure and temperature. Over time, the rubbing surfaces of the parts wear out, and the seals lose their tightness, which is why it begins to penetrate into the combustion chambers. engine oil. The combustion conditions of the air-fuel mixture worsen as the lubricant burns out and forms a hard deposit on all accessible surfaces:

• piston skirts and chamber walls - first of all;
• side surfaces of the pistons in contact with the cylinder walls;
• the front planes of the valves and their internal surfaces adjacent to the seats;
• grooves for piston rings and holes for draining liquid lubricant (located deep in the groove of the oil scraper ring).

At the same time, the electrodes of the spark plugs become covered with soot, which reduces the quality of spark formation.

When the amount of lubricant penetrating inside the cylinder becomes critical, black coke clogs all possible cracks and holes. Because of this, the rings get stuck in the grooves (in the jargon they lie), causing the actual compression in the cylinders to drop by 50-90%. A valve that is burnt on the seat side will not close hermetically, and then the compression pressure will drop completely to zero - the cylinder will completely fail. The consequences can be prevented if the engine is decarbonized in time.

When to decarbonize the engine?

The procedure gives a positive result if performed in a timely manner. You can’t delay it too much - you’ll just waste your money, because chemicals are not cheap. When decarbonization becomes useless:

1. When driving for a long time with high oil consumption. If the engine “devours” 1 liter of lubricant per 1000 km or more, and you do not take any measures for 2–4 months, then get ready to make major repairs. The carbon deposits will clog the rings and oil drain holes so much that chemicals will not help, only mechanical cleaning.
2. If compression in one or two cylinders has dropped to zero. This indicates burnt valves that the cleaner will not pick up.
3. If noise or knocking occurs in the engine, requiring immediate replacement of parts.

You can perform decoking at your own risk, but with the symptoms listed, the chances of success are extremely low. Sometimes the opposite effect is observed - after cleaning, the compression in the engine drops and further driving becomes impossible, the engine loses a lot of power.

The reason for the phenomenon is the same carbon deposits. By covering all accessible surfaces, the coke begins to serve as a seal instead of the piston rings and, together with the lubricant, creates increased pressure in the chamber, sufficient to ignite the fuel mixture (so-called oil compression). After cleaning, the seal deposit disappears, and the pressure in the cylinders drops due to wear of the CPG elements. The motor refuses to work.

Practice shows that a special liquid for engine decarbonization should be used at a consumption of engine lubricant of 0.3–0.5 liters per 1 thousand kilometers. At this moment, intensive carbon deposits begin, but irreversible consequences have not yet occurred. If the culprits of the oil burn are valve seals, then after the procedure they can be changed and driven over 20 thousand km, provided that the CPG is in satisfactory condition.

Selecting a cleaning product

In car stores and markets you can find a wide variety of chemicals that are declared by manufacturers as effective cleaners of coke from power unit parts. Which of them are used most often and have earned a positive reputation:

• Mitsubishi Shumma;
• GZox;
• BJ-211;
• Lavr.

The first 2 drugs are liquid in aerosol packaging with a capacity of 220 and 300 ml, respectively, pumped into cylinders through a tube. The remaining two products are poured in using a syringe. As a rule, one package - a can or bottle - is enough to service one four-cylinder engine with a working volume of up to 1.6 liters. For higher power engines with 6–12 cylinders, 2–3 tanks will be needed.

A few words about the best way to clean the engine. The undisputed leader is considered to be Mitsubishi Shumma, tested in practice by many master mechanics. There is only one drawback - the price of the drug is too high (about 30 USD per can). An alternative is GZox aerosol, which shows similar results at half the cost. Liquids BJ-211 and Lavr close the list of the best cleaners present on the automotive chemicals market.

Advice. Should not be used to decarbonize the engine. modern car old “old-fashioned” methods, pouring a mixture of acetone with solvent (kerosene) and other ineffective liquids into the cylinders. They act too slowly and do not dissolve carbon deposits well.

Preparing to remove carbon deposits

Before decarbonizing the cylinder-piston group of the engine, it is necessary to thoroughly prepare. First of all, allocate time – the entire procedure takes 8–15 hours. The exact holding time is indicated on the packaging of the cleaning fluid. It is advisable to time the operation at the time of oil change, since some of the dissolved coke will drain into the crankcase and the lubricant will have to be changed in any case.

To decarbonize a worn-out engine yourself, you should prepare the following materials and spare parts:

• cleaning agent;
• engine oil and filter;
• new spark plugs;
• bolts - plugs that fit the thread instead of lambda probes.

There is no need to create special conditions for carrying out work; it is enough to have a flat area near the house or a garage. It is advisable to have a compressor as equipment, but you can do without it.

The preparatory stage includes the following operations:

1. Warm up the power unit to a temperature of 60–70 °C, which is necessary to activate most cleaners.
2. Unscrew the oxygen sensors from the exhaust tract and install the plugs from the bolts. The goal is to protect expensive electronic components from clogging and soot.
3. Support the vehicle with wheel chocks and lift any drive wheel.

Decarbonization instructions

When warming up the power unit before cleaning, it is worth pouring a flushing compound into the crankcase - “five minutes” in order to remove dirt from the oil channels as much as possible. You should also measure the compression on a hot engine in advance, this will help you see the result before and after decarbonization.

Perform further actions in this order:

1. Carefully read the instructions on the cleaning product packaging and find out how much liquid needs to be poured into each cylinder of your engine.
2. Remove the spark plugs and clean them thoroughly with a metal brush, rinse with gasoline and blow out.
3. While turning the drive wheel by hand with 5th gear engaged, set all pistons to the middle position, measuring the depth with a long screwdriver.
4. Lowering the tube one by one into the spark plug holes, fill the cylinders with aerosol from a spray can. Decarbonization of the "Lavr" engine is carried out using a syringe (included with the drug).
5. Screw the spark plugs back in without tightening them all the way.
6. Leave for 8–15 hours, periodically moving the crankshaft by turning the wheel. The goal is to help fluid penetrate between the piston rings.

After the time specified in the instructions has passed, unscrew the spark plugs again and try to pump out the dissolved dirt from the cylinders with a syringe, and then blow it thoroughly with a compressor. The better you can clean out the remaining coke, the faster the engine will start.

Install the old spark plugs and start the engine without increasing the speed above 1500 rpm. Let it warm up and “spit out” pieces of carbon deposits through the exhaust tract. After 10–15 minutes of engine operation, when the smoke from the exhaust decreases, return the lambda probes to their place and begin replacing the engine lubricant.

Screw in new spark plugs last, after cleaning the power unit and changing the oil. Before installing spark plugs, re-measure the compression and make sure that the measure has a positive effect. If the result is negative, begin preparations for disassembling and overhauling the motor.

Decarbonization diesel engine differs in the method of filling the cylinders with a chemical agent. Since there are no spark plugs, the fluid is poured through the injector holes. The latter will have to be dismantled after first releasing the fuel pressure in the system and turning off the pump.

Sooner or later, carbon deposits form in any engine. First, the rings become coked, then deposits appear on the valve system in the combustion chamber. The addition of special additives, the use of high-quality oil and proper operation significantly reduce the intensity of contamination, but do not eliminate the problem completely. Motorists have to resort to special vehicles.

Coking of rings: reasons

If the engine system is in good working order and the vehicle is used correctly, minimal carbon deposits will form. A certain amount of oil still enters the combustion chamber, causing the build-up of a layer of soot/varnish on the cylinder-piston group. In this case, decarbonization may be necessary once per 100 thousand km or even less often.

But the influence of additional factors can speed up the process. Premature coking is provoked by:

• overheating of the engine, its boiling - if the piston heats up above the coking temperature, carbon deposits form much more intensely;
• low fuel quality;
• low quality motor oil, the presence of questionable additives in it;
• engine oil does not correspond to that recommended by the manufacturer;
• driving with a cold engine;
• constant driving at low speeds;
• constant driving under increased loads;
• violation of the formation and/or combustion of the air-fuel mixture; overly enriched fuel mixture is also detrimental to the engine.

First of all, the products of oil combustion settle on the oil scraper rings, as well as on the pistons, inside the combustion chamber, and on the valves. In the latter case, carbon deposits prevent the valve from fitting tightly to the seat, which leads to incorrect engine operation.

The following signs indicate the need for decoking:

• increased oil consumption (the norm is 100 g per 1 thousand km);
• change in exhaust color to bluish or white;
• reduction in engine power;
• decreased compression in one or more cylinders;
• increase in exhaust toxicity, appearance of a characteristic odor.

What are the consequences of coking of piston rings?

Even with slight carbon deposits, the operation of the cylinder-piston group is disrupted. More and more oil enters the combustion chamber, and carbon deposits begin to accumulate more intensely. If decarbonization is not carried out in time, the layers of soot will thicken until the elements of the propulsion system completely fail.

A large layer of coke on the valves leads to a decrease in compression in the cylinders, later to burnout of the valves and extrusion of the piston rings.

Decoking of engine rings: how is it done?

If a motorist decides to clean the engine himself, he needs to buy a special composition for hard decarbonization and use it according to the instructions. When purchasing, you should pay attention to what type of engine (petrol, diesel) the product is intended for, as well as the volume of the container. Some packages are designed to fill only one cylinder.

Sometimes car owners prepare the cleaning liquid themselves by mixing acetone and kerosene (2:1 or 1:1). In terms of effectiveness, such products are inferior to professional formulations; its use can do more harm than good.

Do-it-yourself decarbonization is carried out in several steps:

• The engine warms up to operating temperature. It is necessary to let it idle for 5-10 minutes. This will allow the cleaning composition to better cope with its task.
• High-voltage wires are removed from the coils.
• The spark plugs are removed.
• Low voltage wires are removed.
• The oil is drained into a clean container. You will need it later.
• Cleaning liquid is poured into the cylinders through the spark plug hole. You can use a syringe. It is more efficient to decarbonize all cylinders at once.
• The pistons are set to the middle position. To do this, you need to turn the crankshaft and, using an auxiliary tool (you can use a wire), set the piston in the desired position.
• The spark plugs are screwed in slightly (but not completely), and the vehicle is left alone for up to 12 hours (depending on the manufacturer's instructions on the cleaning solution packaging).
• After 6-12 hours, the candles are carefully unscrewed. If you do this carelessly, the decarbonizing liquid will “fly away” into the crater, and the softened carbon deposits will splash out.
• The oil cap is unscrewed and the liquid in which the carbon has dissolved is carefully drained.
• The oil drained at the beginning of the procedure is poured back into the engine.
• Without replacing the spark plugs and ignition coil, the engine cranks on the starter for 5-10 minutes.
• The system is being assembled. After this, you need to drive the car for 20 minutes for better cleaning. During the process, it is recommended to increase the speed to 4000 from time to time.
• Finally, the oil and oil filter are changed. Sometimes the spark plugs also need to be replaced.

When driving after the procedure, you may notice that the exhaust has an unnatural color. It is recommended to perform a test drive away from busy highways and traffic police posts.

Prevention of coking or easy cleaning

Decarbonization of engine rings can be done in a gentle manner. To do this, a special composition for gentle cleaning is added to the engine oil before changing it. Then the car is operated in gentle conditions for 100-300 km, after which the oil is changed.

In recent years, you can find products for the so-called dynamic decarbonization on sale. A special composition is added to the fuel and, entering the combustion chamber with it, penetrates the coke layer, destroying it. The vehicle is operated under normal conditions. This method is also suitable for prevention, but not for eliminating severe soot.

Cleaning Features

Despite its apparent simplicity, the procedure for cleaning the engine has many nuances and complexities. Before you begin, you should learn how to decarbonize the engine correctly. An error may require major repairs or re-cleaning at a car service center.

Important details:

• The quality of cleaning depends on the quality of the composition. If you decide to save on the services of a specialist, then do not skimp on at least the composition for decarbonization.
• Violation of the procedure technology leads to incomplete dissolution of carbon deposits. For example, rapid cooling of the engine in cold weather reduces the effectiveness of the solvent. Therefore, in the cold season, it is better to carry out decarbonization in a workshop where there is a special room.
• Solvents are toxic and hazardous to health. Working in a room without good ventilation (for example, in a closed garage in winter), the car owner can get seriously poisoned.
• Features of the procedure depend on the type of engine. It will be difficult for a non-specialist to remove the spark plugs of a V-shaped or boxer engine and fill in the solvent. Boxer engines have a non-standard arrangement: the spark plugs are difficult to reach, and the cleaning composition can leak if not handled carefully.
• To decarbonize a diesel engine, you will have to remove the injectors. To do this you will need a special tool.
• Without experience, it is difficult to set the pistons exactly in the middle position.
• You need to guess the amount of solvent being poured. The volume of the combustion chamber depends on the specific motor, and the instructions for using the cleaning agent are almost the same. It takes years of experience to know how much solvent to add. If you overdo it, the excess will get into the oil mixture and damage the rubber parts. If you don’t add enough, the carbon deposits will not be cleared.

After decoking, the engine regains its original performance qualities, its service life increases - but only if all the work was done correctly. If you do not have experience and value your car, it is better to contact a service center for decarbonization.