The accumulation of charcoal in the combustion chamber is a natural but devastating process that every ICE car owner faces. Carbonization Parts reduce compression, ignition and eventually costly overhauls. Many motorists delay the solution for fear of the complexity of the procedure, but modern autochemistry allows cleaning without removing the cylinder head.
Timely removal of sediments restores the geometry of the chamber and releases piston rings, which are often buried due to coking. In this article, we will examine in detail the proven methods of decoking, compare the effectiveness of different drugs and give a step-by-step algorithm of actions. Restoration of ring mobility without opening the engine is real, if you follow the technology and use high-quality compositions.
Ignoring the problem leads to the fact that the layer of coar becomes thicker, acting as a thermal insulator and causing the engine to overheat. Critical is considered a layer of coar thickness of more than 0.5 mm, which is able to change the degree of compression and cause detonation. Understanding the physical processes inside the cylinder will help you choose the right cleaning method and avoid errors that can finish off a good unit.
Causes of the formation of sodium and its impact on the work of the ICE
The main source of sediment is the incomplete combustion of the fuel-air mixture, and in ideal conditions, gasoline or diesel burns completely, leaving only water and carbon dioxide. enriched Or when you use high-carbon oil, you make carbon solids, and they settle on the walls of the cylinder, the bottom of the piston, and the valves, and they form a dense crust.
The most dangerous is what's called oil coke, which is produced by burning motor oil. oil-cap They lose elasticity or the stiff rings let the lubricant into the combustion chamber, and this type of stain is very hard and melting point, making it difficult to remove, and not only reduces the volume of the chamber, but it also disrupts the heat sink from the piston.
⚠️ Attention: Operation of the engine with strong swelling on the bottoms of the pistons can lead to burnout of the valves and destruction of the partitions of the piston rings due to local overheating of the metal.
The effect of deposits on the operation of the engine is manifested in the form of floating idling turns and loss of traction at low revs. DetonationThe scaling system, which is caused by the increased compression and the hot spots of the coke, can destroy the shaky piston group in minutes, so the fight against carbonization is not only a matter of fuel economy, but also of safety in the car.
Diagnostics of the state of the combustion chamber and piston group
Before starting chemical cleaning, you need to assess the degree of contamination and the general condition of the engine. The primary sign of the need to clean is high oil consumption and the presence of blue smoke from the exhaust pipe. However, a visual examination through the candle hole gives a more accurate picture, to twist the spark plugs and use the flashlight to assess the condition of the bottom of the piston.
A more accurate method is to measure compression and conduct a leak test (P-test). If the compression is much lower than normal, but after pouring a small amount of oil into the cylinders, the readings increase sharply, this is a sure sign of the occurrence of rings. Endoscopy is the most informative diagnostic method, allowing you to see the condition of the valves and walls of the cylinder without disassembly.
To conduct a high-quality diagnosis, you will need the following set of tools:
- 🔧 Compressometer for measuring pressure in cylinders.
- 🔦 A powerful LED light or boroscope.
- 📝 Diagnostic scanner for error analysis on the knock sensor.
- 🧪 A syringe and oil sample tube (if necessary).
It is also important to analyze the color of the lobe. Dry black plaque often indicates over-enrichment of the mixture or problems with the ignition system. Oily, sticky black charcoal indicates oil ferment. Bleached or grayish can be a sign of antifreeze entering the combustion chamber, which requires not cleaning, but serious repair of the gasket gasket.
Review of chemical means for engine decoking
The autochemical market offers a variety of combustion chamber cleaning products that can be divided into several categories by composition and principle of operation, the most popular are solvent-based and surfactants, which soften the soda into gruel, which is then burned out or removed through the exhaust system.
A separate group of drugs containing active metals (burning catalysts) are not only dissolve sediments, but also contribute to their burning at lower temperatures, preventing the formation of new layers. Japanese compositions They are often based on the principles of soft decoking added to fuel, while domestic and European brands more often offer concentrates for direct filling into cylinders.
Comparative specifications of popular types of funds:
| Type of instrument | Method of application | Efficiency | Aggressiveness |
|---|---|---|---|
| Straight bay (concentrate) | In cylinders through candle holes | High. | High. |
| Fuel additive | Additive to the gas tank | Medium (prevention) | Low. |
| Oil additive | Supplement to motor oil | Medium | Medium |
| Aerosol through the inlet | Spraying into the intake manifold | High (valves) | Medium |
The dangers of using acetone and solvent
Using pure acetone or aggressive solvents in older rubber sealed engines can cause them to swell and break down. Modern decoxing contains corrosion inhibitors and additives that protect rubber parts, which are not found in household solvents.
When choosing a drug, you should pay attention to the manufacturer's recommendations regarding compatibility with catalytic converters. Aggressive chemistry It can disable the catalyst by clogging its cells with the decay products of the charcoal. For engines with high mileage, it is better to choose compounds marked "Soft" or "For mileage engines", which act more delicately.
Technology of decoking by direct bay method
The method of direct pouring liquid into the cylinders is considered the most effective for removing the coar with the pistons and rings. The process requires preparation: the engine must be heated to the operating temperature to ensure maximum expansion of the metal and softening of the deposits. After warming up, the car is installed on a flat platform and allowed to cool slightly so that the temperature drops to 50-60 degrees.
Then all spark plugs (or diesel injectors) are twisted out. The pistons are set to the middle position, and each cylinder is filled through a syringe with a tube with a calculated amount of decoxer (usually 30-40 ml per cylinder). It's important to distribute the fluid. on the walls of the cylinder, scrolling the crankshaft with a starter a couple of times without candles.
☑️ Checklist for preparation for decoking
After pouring, the candles are wrapped (sometimes it is recommended to insert old, non-working candles to create pressure as the liquid expands), and the car is left for 6 to 24 hours, during which time the chemical reaction of the soda dissolves. Time control Here it is critical: to overstay the drug longer than specified in the instructions is not recommended, as it can penetrate the crankcase and dilute the oil.
⚠️ Warning: When scrolling the engine after pouring the liquid (before final assembly), be sure to turn off the ignition coils or nozzles to avoid hydraulic shock and damage to the engine by incompressible liquid.
After the exposure time, the candles are twisted out, and the engine is scrolled by the starter for 5-10 seconds to remove the remaining liquid and dirt from the cylinders. After that, the candles are put in place, and the engine starts. The first minutes of work can be accompanied by severe smoke and instability of revolutions - this is normal, since dissolved soak burns out.
Cleaning through the intake manifold and fuel system
If access to candles is difficult or the engine design does not allow the use of the direct flood method, cleaning through the intake manifold is used. This method is especially effective for removing deposits from the intake valves and the throttle, where the straight bay does not reach.
The engine starts and warms up. Then the fuel supply is cut off (or a special adapter is used), and the engine starts to operate on the cleaning compound supplied through the throttle. Engine rotations They are maintained at 2,000-2,500 per minute, creating a "gas mixture" effect that actively cleans the combustion chambers. The procedure takes about 20-30 minutes.
The alternative is to use highly concentrated fuel additives, which are poured into the tank in a proportion well above the usual preventive dose. Such a method It requires the entire tank of fuel to be produced in a gentle manner, without any sudden acceleration, which is the longest, but also the safest, way for rubber seals to be made.
When cleaning through the intake, try not to allow a sharp discharge of gas, so that the liquid does not fall sharply in a large volume into the cylinders, which can cause hydraulic shock.
The effectiveness of this method depends on the type of injection. In distributed injection engines, the fuel washes the valves, helping to clean. Direct injection (GDI, TFSI) valves are not washed with fuel, so the method of direct pouring or steam cleaning for them are the only effective options for combating swelling on the valves.
Final stage: oil and filter replacement
After the decoking procedure, the replacement of the engine oil and filter is a mandatory step. Aggressive components of the cleaning fluid, trapped through the rings in the crankcase, significantly reduce the lubricating properties of the oil. Operating the engine on the "waste" oil after cleaning is unacceptable and can lead to oil starvation and bullying.
It is recommended to wash the engine with a special washing oil before the final filling of the new oil for 5-10 minutes of idling, which will remove the remains of the decoxer and the suspension of dirt that has settled in the pallet. Oil filter It should also be replaced, as it could be clogged with the decay products of the coarse.
After changing the oil, you must let the engine work at idle for 5-10 minutes, monitoring the oil pressure on the sensor (if any) or indicator on the dashboard. First run After the procedure, it is better to do it in a calm mode, avoiding high turns, so that the new oil is distributed to all nodes and forms a protective film.
High-quality decoking does not require a repetition of the procedure at once. With normal operation and high-quality fuel, the effect is maintained by 20-40,000 kilometers of mileage.
In conclusion, decoxing is a regenerative measure, not a panacea. If the engine has mechanical wear on the cylinders or broken ring partitions, the chemistry will not bring back compression. However, as a preventive measure or a way to extend the life of the engine before the sale / season, this method has proven to be highly effective and affordable.
Can I use a cold engine to drive?
It's not recommended. On a cold engine, the gaps between the parts are minimal, and the chemical reaction is sluggish. The liquid may not have time to act and will drain into the crankcase, diluting the oil, or, conversely, will get stuck in the top of the cylinder, causing corrosion. Warming up to operating temperature is necessary for the expansion of the pistons and activation of the composition.
Is it true that after the engine is decocted, it will start eating more oil?
It's a common myth that a temporary increase in oil consumption is possible if the engine has worn out the oil caps and the aggressive chemistry has finally finished their elasticity, but in most cases, the oil consumption drops as the carbon-free rings start to work normally and remove the excess lubrication from the cylinder walls.
Should I change the spark plugs after the procedure?
It is desirable, but not necessary, if the candles are new. Old candles may be contaminated with the products of burning of sodium and chemicals, which will lead to ignition failures. If the candles are old, they should be replaced in advance to have a stock of clean ones for installation after cleaning. During the process of working on the decoxter, the candles can fail due to the ignition.
How often should I do the decoding?
Preventive soft additives can be done every 10-15 thousand km (with every second oil change). Aggressive cleaning with the bay into the cylinders - only when symptoms appear (oil odor, loss of compression) or before selling a car, but not more often than once in 40-50 thousand km, so as not to harm rubber seals.