How to clean the stain on pistons: effective tools and technologies

Padding on pistons is not just an aesthetic defect, but a serious technical deviation that can significantly reduce the resource. piston-groupIn the process of operating the internal combustion engine, solid deposits of combustion products of the fuel-air mixture are inevitably formed on the walls of the combustion chamber, the bottom of the piston and the piston rings. carbonThey are made up of unburned hydrocarbons, resins and metal particles that coke over time and turn into a strong crust.

Ignoring the problem leads to the fact that ringing It becomes inevitable, compression in the cylinders falls, and oil and fuel consumption increases rapidly. The engine starts to work intermittently, losing traction and thrust. Car owners often wonder how to clean the load on the pistons to avoid costly overhauls or a complete replacement of the power unit. The choice of method depends on the degree of neglect of the situation and the willingness of the owner to intervene.

There are two basic approaches to this problem: chemical cleaning without disassembling the engine (called "discoxing") and mechanical cleaning with complete or partial defects in the engine. Chemical reagents are able to dissolve soft deposits, but often powerless against fossilized coke, which requires physical removal. Understanding the nature of contaminants and choosing the right ones. cleaning-stuff These are key success factors in restoring the engine to work.

Causes of deposit formation and their effect on the operation of the engine

The formation of the layer of carbon monoxide is a complex chemical process, depending on many factors. The main catalyst is the low quality of the fuel, containing a large number of heavy fractions and impurities. When such fuel is burned, a significant amount of unburned carbon remains in the cylinders, which settles on hot surfaces. mineral-oil low quality or late replacement when the lubricating liquid loses its properties and begins to burn.

Of particular concern is what's called "oil charcoal," where oil enters the combustion chamber through worn-out oil caps or worn piston rings, burning with gasoline or diesel leaves behind a viscous, sticky coating that hardens over time. cokingAs a result, the porous structure of the soda absorbs new portions of the oil, triggering a self-reinforcing cycle of pollution.

⚠️ Attention: A thick layer of coar on the bottom of the piston reduces the volume of the combustion chamber, which leads to increased compression and detonation, which can cause valves to burn or even the piston to break.

The effect of deposits on the engine is devastating, and the piston rings' grooves, which are soaked up in the grooves, make them less mobile, so that the rings don't fit tightly into the cylinder walls, cause gases to break through the crankcase and compression to fall, and the swelling on the side of the piston can scratch. john (relief of the cylinder surface), causing accelerated wear of the piston-cylinder pair.

List of main symptoms indicating a critical condition of the piston group:

• 📉 A noticeable drop in compression in one or more cylinders during diagnosis.
• 💨 The appearance of gray or black smoke from the exhaust pipe, especially when gassing.
• 💧 Increased consumption of motor oil (more than 0.5-1 liters per 1000 km of run).
• 🔥 Unstable operation of the engine at idling and "triple".

It is important to understand that modern direct-injection engines (GDI, TFSI, FSI) are even more prone to the formation of sodium, and in such engines the fuel stream does not wash the intake valves, so the sodium accumulates faster and requires more aggressive cleaning methods.

Chemicals for decoking: review and comparison

The automotive chemicals market has a wide range of products designed to remove the swelling without disassembling the engine, which are divided into several categories by type of exposure and composition. solvent And alkaline components that are poured directly into cylinders through candle holes, which are designed to soften and dissolve coke deposits on the rings and walls.

One of the most well-known groups is dimexide or esters, which are highly penetrating and effectively destroy the structure of solid sodium. However, be careful: aggressive chemicals can damage rubber seals, gaskets and paint coatings under the hood.

Comparative table of popular tools for decoking:

Name of the means	Type of base	Efficiency	Risks for rubber
Laurus (Lavr)	organic solvent	High.	Medium.
Gzox	Petroleum distillates	Medium	Low.
Greenol Reanimator	Alkaline composition	Very high.	Highly
Edial	Fuel additive	Low (prevention)	Missing.

And the products that we add to the fuels, they're very gentle and they're very gradual, and they clean the fuel system and the combustion chamber as you drive. Edial or Hi-GearThey are more suitable for the prevention or removal of light deposits, but are unlikely to cope with a seriously coked motor. Deep cleaning requires direct contact of concentrated solution with soda.

When choosing a chemical, it is important to pay attention to the manufacturer's recommendations: Some modern engines with ceramic cylinder coating or special piston rings can be sensitive to aggressive components of decoxers, in which case it is better to use certified dealerships.

Mechanical cleaning: technologies and tools

When the chemistry is impotent or the level of contamination is critical, the only way out is mechanical cleaning, which involves disassembling the engine, removing the piston group and physically removing the coal, which is the most time-consuming, but also the most effective way to visually assess the condition of parts and eliminate defects that are not available to chemistry.

Machining uses a variety of tools and abrasives. Traditionally, brushes with brass or steel bristles, scrapers and rags soaked in a solvent or acetone. It is important not to damage the surface of the piston, especially if it has a special graphite spray or skirt is made of soft alloy. Excessive diligence when cleaning can disrupt geometry or damage the antifriction layer.

Modern technology uses ultrasonic baths to clean pistons, and the parts are immersed in a special chemical solution that, when exposed to ultrasonic waves, creates a cavitation effect, and when bubbles collapse near the surface of the metal, they knock out tiny particles of sofa even from hard-to-reach places, such as piston ring grooves. most gentle And quality.

• 🛠️ Using wooden or plastic scrapers to remove large layers of sodium.
• 🧪 Soaking parts in kerosene or diesel fuel for several hours before cleaning.
• 🌀 Use of sandblasting (only for certain types of pistons and with great care).

⚠️ Attention: In mechanical cleaning, it is strictly forbidden to use metal brushes on the aluminum surfaces of pistons, which will lead to the appearance of furrows that will work as an abrasive, accelerating the wear of the cylinders.

After mechanical cleaning, you need to thoroughly wash all the parts and blow out the oil channels with compressed air. Residues of abrasive or detached carbon in the channels can cause oil starvation and rapid failure of new liners. The quality of surface preparation directly affects the life of the repaired engine.

Special attention should be paid to cleaning the grooves under the piston rings, which is where the most common laying occurs, using special tools or sharpened wooden sticks to avoid damaging the edges of the grooves, Any scratch on the end of the groove can lead to breakage of the ring in the future.

Popular methods and "heavy artillery"

Motorists are popular with traditional recipes that are often as effective as expensive autochemistry. One of the most famous is dimexide, a drug with a powerful solubility. It actively breaks down organic deposits and soda. However, its use requires extreme caution, since dimexide is aggressive to certain types of plastics and rubber, and can also cause chemical burns to the skin.

Another common method is to use a 1:3 mixture of acetone and motor oil, which is poured into the cylinders at night, acetone softens the hard fractions of the soda, and oil provides lubrication and prevents corrosion, and the effectiveness of this cocktail is high, but there is a risk of damage to the paint coating of the engine if the mixture hits the external surfaces.

Another option is to use kerosene or a mixture of kerosene and gasoline, which penetrates the pores of the sodium well and softens it. To enhance the effect, the mixture is often left in the cylinders for 10-12 hours. It is recommended to periodically rotate the crankshaft so that the liquid penetrates deeper. However, kerosene washes the oil film, so after the procedure you need to immediately start the engine and warm it up.

Why is Dimexide Dangerous to the Engine?

Dimexide can destroy some of the polymers used in modern engines (for example, plastic elements of valves or sensors), and it also contributes to the oxidation of oil, so after its use, you need to replace the oil and filter.

The "heavy artillery" also includes the use of alkaline solutions, for example, means for cleaning ovens (type). ShumanitAlkali eats organics well, but it is completely incompatible with aluminum, and can only be used for steel parts or with measures that exclude contact between the alkali and the aluminum parts of the piston, which is almost impossible to do at home.

The principle of using folk remedies is "do no harm." Experiments with aggressive chemistry are justified only on old, not sorry, or when other methods have not worked. Modern engines with complex geometry and many sensors are better to use proven industrial compounds.

Technology of carrying out decoking DIY

The decoking procedure, although considered a method of indiscriminate repair, requires careful preparation and adherence to the technology. Sequence disruption can lead to hydraulic shock or damage to engine elements. Before starting work, the car must be warmed to operating temperature to widen the thermal gaps and the chemistry works more efficiently.

Then the engine is jammed, the spark plugs (or nozzles, depending on the design) are twisted out, and the pistons are placed in the middle position. This is important so that the liquid does not immediately go into the crankcase and is evenly distributed around the piston. Each cylinder is filled with an estimated amount of the product (usually 30-50 ml, according to the instructions for the drug).

After pouring, the candles are twisted (without tightening until the end to create pressure) or leave the holes open but closed with rags so that the vapors do not evaporate. The engine is left to oxidize for the time specified by the manufacturer of the product (usually from 1 to 12 hours). It is recommended to turn the crankshaft slightly, so that the softened soak is better separated.

Algorithm of action:
1. ICE heating to 40-50 degrees.
2. Unwringing of candles/nozzles.
3. Installation of pistons in the middle position.
4. Filling the decoker into the cylinders.
5. Exposure (1-12 hours).
6. Blowing cylinders and scrolling with a starter.
7. Assembly and launch.

After exposure, remove the remaining liquid from the cylinders, and then you scroll the engine several times with a starter with twisted candles, before closing the candle wells with rags, so that dirty slurry does not splash the hood space, then the candles are installed and start the engine. The first minutes from the exhaust pipe will be poured thick white smoke — this burns out the soda and the residue of chemistry.

It is important to let the engine run at idle speeds of 10-15 minutes, periodically increasing the speed to 2000-2500, to burn the residue of the coal from the exhaust system, and then you can make a trip in dynamic mode to finally clean the cylinders under load.

Prevention of the formation of sodium and caring for the engine

The best way to control carbon monoxide is to prevent it: regular use of quality fuel in proven gas stations significantly reduces the risk of solid deposits; fuel with a lower octane number burns more slowly and with more residues, which directly leads to coking.

Compliance with engine oil replacement intervals is the second key factor: Old oil loses its detergent properties and begins to burn actively, forming lacquer deposits. For engines operating in the urban cycle (start-stop mode), it is better to reduce the replacement interval by 20-30% of the regular one.

Periodic engine warm-up and high-speed travel also contribute to self-cleaning. Prolonged driving at low speeds on traffic jams contributes to the accumulation of scorching, while short-term engine operation under load (for example, when overtaking on the track) increases the temperature in the cylinders and contributes to the burning of sediments.

• ⛽ Only refuel at the checked gas stations of large networks.
• 🛢️ Change the oil more often, especially when operating in the city.
• 🏎️ Periodically give the engine load (movement at high speeds).
• 🔍 Every 20-30 thousand km use preventive additives in fuel.

⚠️ Attention: Frequently driving at low speeds ("traction") contributes to the rapid formation of soak. Try not to overload the engine at low speeds and use the range of 3000-4000 rpm more often on the track.

Also worth paying attention to the state of the crankcase ventilation system (PCV). If the ventilation valve is jammed or the system is clogged, the pressure of the crankcase gases increases, and oil enters the inlet and cylinders more actively, accelerating the formation of sodium. Regular inspection and cleaning of the ventilation system is a simple but effective preventive measure.

Timely detection of problems with the ignition system (faulty candles, coils) is also important. Misfires cause unburned fuel to enter the exhaust system and settle on the valves and pistons, forming a resinous plaque.

Can I completely remove the stain without disassembling the engine?

It is almost impossible to remove the old, fossilized stain completely without disassembling the engine. Chemicals are effective against soft, fresh deposits and can release the dead rings. However, a thick layer of coke on the bottom of the piston or in hard-to-reach places often requires mechanical intervention. Decoxing is more a means of restoring the mobility of the rings than a method of perfect cleaning.

How often should I do the decoding?

Preventive decoking is recommended every 30-50 thousand kilometers, especially if the car is operated mainly in the city. If the engine has started to consume oil or lost power, the procedure can be carried out unplanned, but provided that there is no mechanical damage to the CNG.

Is the scaling dangerous for modern engines?

For modern direct-injection engines and sophisticated exhaust neutralization systems (catalysts, particulate filters), aggressive decoking can be dangerous. Combustion products can clog the particulate filter or damage the catalyst. In addition, some formulations can destroy polymer seals. Before using, be sure to check the compatibility of the product with your type of motor.

Will the decoking help if the engine is already consuming oil in liters?

If the oil consumption is more than 1 liter per 1000 km, the wear of the oil rings or cylinders is likely already critical, or the rings have become dead and lost their elasticity. In such cases, the decoxing has only a temporary effect or does not help at all, requires engine defects and probably replacement of piston rings or cylinder cartridges.