Cleaning the engine from soot: technologies and means

Operation of the internal combustion engine in urban traffic inevitably leads to the formation of a new generation of fuel. carbonaceousThis is particularly true for modern engines equipped with direct fuel injection systems, and marine engine owners often face this even more often, since working at idle speeds while waiting for sleeve release contributes to the active deposition of combustion products.

Nagar doesn’t just contaminate parts, it physically reduces the volume of the combustion chamber, leading to higher octane levels of fuel required and detonation. Sticking of piston rings It's a direct consequence of ignoring the first signs of coking, and it's critically affecting the compression and overall power of the unit, making a once-flashy motor a sluggish, voracious mechanism.

In this article, we will discuss in detail the mechanical and chemical methods of dealing with sediments. scooping We'll look at the difference between prevention and resuscitation of highly contaminated nodes, and evaluate the effectiveness of different chemical formulations.

Causes of formation and the effect of scorching on the engine

The main source of coal is incomplete combustion of the fuel-air mixture, and in marine engines, the situation is aggravated by the use of gasoline with an octane number below the recommended or, conversely, the presence of excess additives. Motor oil, falling into the combustion chamber through worn oil removable rings or the crankcase ventilation system, also burns with the formation of lacquer films and solid particles.

Nagar has a low thermal conductivity, which causes the engine parts covered with this layer to overheat, the edges of the piston and valves, when overgrown with a coat, lose the ability to effectively give heat to antifreeze or off-shore water, which creates conditions for the occurrence of potassium ignition, when the mixture is ignite not from the spark of a candle, but from red-hot particles of soda.

⚠️ Attention: A thick layer of coar can break off and get between the piston and the cylinder head, leading to mechanical bullying and the need for major repairs.

And the sediments also disrupt the valve geometry, preventing them from fitting tightly into the saddles, and the result is that the combustion chamber loses its tightness, and some of the gases break through into the exhaust manifold or cooling system, the engine starts to triple, loses traction, and fuel consumption increases disproportionately to the load.

Symptoms of coking: when you need cleaning

There are a number of indirect signs that you can tell if an engine needs help, and the first thing that you can do is change the way you're idling, or you can start to float around or you can stop when you drop a gas. throttle And the idle regulator is covered with a sticky coating.

The second sign is the appearance of gray smoke from the exhaust pipe when you press the gas sharply, which is a classic symptom of piston rings, the oil does not get off the cylinder walls and burns with the fuel. In advanced cases, the smoke can go on constantly, and the oil consumption can reach a liter per thousand kilometers.

• 📉 The compression drop in one or more cylinders is below the permissible values.
• 🔊 The appearance of metal knocking or detonation when accelerating under load.
• ⛽ A sharp increase in fuel consumption without changing driving style or operating conditions.
• 🌡️ Increased operating temperature of the engine due to deterioration of heat sink.

For accurate diagnosis, compression measurements and, if possible, cylinder endoscopy are required, visual examination through the candle hole will allow you to assess the degree of contamination of the pistons and valves. chemical-cleaning Mechanical removal of the stain is necessary.

Chemical decoking: liquids and aerosols

The most popular method among outboard motorists is to use special decoking fluids, which are poured directly into cylinders through candle holes, and a chemically aggressive medium dissolves the solid deposits and softens the coke, turning it into an emulsion, which is then removed when the engine is running.

The procedure requires strict technology: the engine must be warmed to operating temperature, then the spark plugs are twisted, a certain amount of means is poured into each cylinder, after which the candles are placed back or the holes are closed with a rag, the motor is left to oxidize for 30 minutes to several hours, periodically turning the crankshaft.

What happens if you over-restrain the device?

If you leave the aggressive chemistry in the cylinders for more than 12 hours (for some formulations), it can penetrate through the rings into the crankcase oil, which will dissolve the additives in the oil and lose its lubricating properties, which is dangerous when you first start.

It's important to remember that chemistry is only effective when there's direct contact with the sodium. If the rings are completely buried and the fluid is jammed from the piston grooves, the result may be zero, and in such cases, you need to have a mechanical stirring or foam compounds that better penetrate hard-to-reach areas.

Mechanical cleaning and ultrasonic technologies

When chemistry doesn't work, mechanical techniques come to the rescue, and the most affordable of them is cleaning the piston group without completely disassembling the engine, so-called soft mechanics, which involves using special brushes and scrapers through candle holes to remove large growths from the bottom of the piston.

A more radical method is disassembly of the engine and defectiveness: the cylinder head is removed, the valves are cleaned in an ultrasonic bath or sandblast (with care not to damage the saddle), the pistons are soaked in special solutions, and the combustor's charcoal is cleaned manually, which is guaranteed, but requires high skill of the performer.

Cleaning method	Efficiency	labour-intensiveness	Risks.
Liquid decoxing	Medium	Low.	Coking rings for errors
Foam cleaning	High.	Medium	Hydro-impact with excess foam
Mechanical (disassembly)	Maximum	High.	Human factor in assembly
Ultrasound (GBC)	High.	High.	Aluminum damage

Ultrasonic cleaning is particularly effective for injectors and valves. Cavitation bubbles, when they collapse, knock the swell out of the metal's microscopic pores. However, this method is only applicable when disassembled to clean the internal cavities of cylinders.

Technology of cleaning of throttle and intake manifold

The inlet tract deserves special attention. The oil fog here is from the crankcase ventilation system and the fuel vapor. Over time, the throttle passage section decreases, which disrupts mixing. This is critical for outboard motors, because it affects the stability of operation at small strokes.

Throttle cleaning should be done using a special aerosol carburetor cleaner. It is important not to damage the graphite spray on the valve, if it is provided by the manufacturer. Aggressive solvents can wash this layer, which will lead to air suckers and unstable operation.

Intake manifold cleaning often uses the "drip-tray" method, where the purifier is dosed into the intake pipe on the engine running, which allows the valve and combustion chamber to be cleaned "hot", but this method requires caution not to cause uncontrolled ignition or hydraulic shock with a liquid.

After cleaning, the procedure for adapting the throttle valve must be performed.ECU) the opening of the valve shall be remembered: the adaptation shall be reset by means of a diagnostic connector or by a special sequence of actions with the gas peal and ignition.

Prevention of sodium and selection of the right materials

The best way to control the pollution is to keep it from forming, especially in terms of fuel quality. For outboard motors, which are often run in partial load mode, it is critical to use gasoline with the octane number specified in the instructions. Low-octane fuel burns more slowly and leaves more carbon.

The second important aspect is temperature: engines that are constantly "traction" at low revs, tend to coking, periodically you need to let the engine work at high revs (in safe mode) so that the high temperature burns out the light fractions of sediment, this is especially true for two-stroke engines, where the coar is formed due to the combustion of oil.

• 🛢️ Use only certified motor oils with manufacturer’s tolerances.
• ⏱️ Keep the oil change intervals, without waiting for a critical condition.
• 🚤 Periodically give the engine a load at high speeds for self-cleaning.
• ⛽ Add quality fuel additives-cleaners at each refueling.

Also worth paying attention to the ignition system: the wrong angle of ignition advance or faulty candles lead to afterburning of the mixture in the exhaust tract or, conversely, to incomplete combustion. Regular check of spark plugs helps to indirectly judge the processes occurring inside the cylinder.

⚠️ Attention: Do not use "traditional" cleaning methods, such as adding water to the collector or using solvents of unknown origin, which can lead to hydraulic shock or the destruction of rubber seals.

Frequently Asked Questions (FAQ)

Can I use a cold engine to drive?

No, it's a big mistake. Most compounds are designed to react at high temperatures, and on a cold engine, the product can't dissolve the carbon dioxide effectively, and it just drains into the crankcase, spoiling the oil, and the engine must be warmed to operating temperature before the procedure.

Should I change the oil after the oil is removed?

Yes, it is. In the process of cleaning, some of the dissolved soda and chemicals inevitably enter the crankcase oil, reducing its lubricating properties, and even if you used "sparing" formulations, the oil and filter should be replaced immediately after the procedure is completed and the engine warms up.

Will the engine be able to clean up if the engine is already eating oil in liters?

If the oil consumption is caused by the rings, the decoying can help, but only if the rings have not lost their elasticity and mobility completely, and if the wear of the cylinders is great or the rings are physically destroyed, only mechanical repair and replacement of parts will help.

How often should the engine be cleaned from the scalp?

Preventive cleaning of the intake system and the use of additives in fuel is recommended every 5-10 thousand motor hours or once a season. Full decoking of cylinders should be done only when symptoms appear (oil consumption, compression drop), usually this occurs once every 40-60 thousand kilometers of equivalent mileage.

Is the decoking dangerous for the catalyst?

If the procedure is done correctly, it is not. However, if too much aggressive chemistry is poured into the cylinders, the combustion can produce compounds that can temporarily poison the sensitive layer of the catalyst, so it is important to strictly follow the dosage specified by the manufacturer of the product.