The carbon monoxide in the combustion engine is an inevitable companion of operation, which over time becomes a serious problem. The products of combustion of fuel and carbon monoxide deposit on the pistons, valves and walls of the combustion chamber, disrupting the thermal regime and the geometry of the gaps. If you ignore the first signs of pollution, you can face potassium ignition, when the engine continues to work after turning off, or a critical drop in compression.
There are many myths that modern oils and fuels leave no traces, and that's a dangerous misconception. Temperature variations And urban traffic modes promote accelerated solid sediment formation, and in this article, we'll look at the physical and chemical processes of sediment formation, as well as proven ways to remove it.
Timely cleaning allows you to return the factory performance and extend the life, we will consider both mild prevention methods and radical mechanical cleaning. It is important to understand that the choice of method depends on the degree of contamination and design of your unit.
Causes of sediment formation and their influence
The main source of sodium is incomplete combustion of the fuel-air mixture, and in ideal conditions, gasoline or diesel burns completely, turning into carbon dioxide and water. low-temperature In a re-enriched mixture, some of the carbon is not oxidized and deposited on hot surfaces, and the quality of the fuel is key: impurities and heavy fractions produce more ash.
The second important factor is the carbon monoxide of the engine oil, and even a good engine uses a small amount of lubricant that enters the combustion chamber through piston rings or oil caps. Synthetic oils They burn cleaner than minerals, but at high loads, they can leave traces, and it is especially dangerous to use oil with an inappropriate tolerance or expired replacement period.
⚠️ Attention: Ignoring the problem of coarse gas can lead to piston rings, which causes a sharp drop in compression and the need for major repairs.
Third, the mode of operation, long idling, frequent short trips without warming up and aggressive driving with sharp accelerations create ideal conditions for coking. combustion-point It may not be sufficient for self-purification, or, conversely, too high, which causes burning of the oil.
Symptoms of engine pollution
There are a number of indirect signs that you can tell that the engine needs cleaning. The first alarm is often a change in the nature of the idling. The engine can start to turn, the vibrations become more noticeable, and the revolutions float for no apparent reason. garlic has broken the tightness The valves or the volume of the combustion chamber changed.
The second is power loss and fuel consumption, and the deposits on the walls of the combustion chamber act as a thermal insulator, causing heat sinks to degrade, causing local overheating and detonation, and the electronic control unit, in an attempt to compensate for the detonation, changes the angle of ignition ahead, which negatively affects the dynamics.
- 🔥 The appearance of black or gray smoke from the exhaust pipe during gassing.
- 🔇 Decrease in the octane number of fuel inside the cylinder due to reduced volume.
- 📉 Compression drop in one or more cylinders.
- 🛑 Check Engine lamp with errors in ignition skips.
And you also have to pay attention to the color of the exhaust, and if you keep getting smoke out of the pipe after you warm up, that's a sure sign that the oil is burning in the cylinders along with the fuel, and the nagar is formed very quickly, creating a vicious circle: more soda, worse than the ring, more oil in the chamber.
Effect of coar on turbine
Nagar can form not only in cylinders, but also on the turbocharger blades, which disrupts the rotor's balance, causes vibrations, and can cause the bearings to collapse, and cleaning the turbine requires removal and defectiveness.
Chemical decoking: a mild method
The most affordable and popular method of dealing with sediment is chemical decoking, which does not require disassembly of the engine and is performed by pouring a special reagent into cylinders or a fuel tank. Active chemistry softens the solid deposits, turning them into gruel, which then burns out or washed out with oil.
There are two main types of chemical cleaning: soft (added to oil before replacing) and hard (filling into cylinders), the first is good for prevention, the second is good for treating existing problems. It is important to strictly follow the instructions of the liquid manufacturer, since aggressive components can damage rubber seals or wash off the oil film.
☑️ Preparation for chemical decoking
The hard-cooking procedure usually takes 1 to 24 hours. After exposure, you need to replace the engine oil and filter, as part of the dissolved soda will inevitably fall into the crankcase. If you ignore the replacement, the abrasive particles can damage the crankshaft liners.
⚠️ Warning: Do not leave aggressive chemicals in the engine longer than the specified time. Some formulations can cause corrosion of metal surfaces with prolonged contact.
The effectiveness of the method depends on the degree of contamination. For mild to medium cases, the result can be great: compression is leveled out, flow rate drops. However, if the rings are already mechanically deposited or coked dead, the chemistry may not help, in which case more serious intervention is required.
Mechanical cleaning and sandblasting
When the chemistry is powerless, mechanics come to the rescue, which involves either partial or complete disassembly of the engine. Removing the cylinder head (CBG) allows you to visually assess the state of the combustion chamber and manually remove hard coke. Metal scrapers are absolutely not allowed, they leave the risks on aluminum.
One of the most effective methods of modern times is to clean a walnut shell or a soda (Soft99, Walblast), which is fed by a jet of compressed air under pressure, and it knocks down the soda perfectly without damaging the metal or leaving scratches, and it allows you to clear out hard-to-reach places that you can't get to with a brush.
Mechanical cleaning also involves checking and replacing the oil caps, often by blowing them in, which means that the oil gets into the cylinders, and replacing these rubber bands, combined with cleaning the valves, is almost like a new engine.
| Cleaning method | Complexity | Efficiency | Risk to the engine |
|---|---|---|---|
| Fuel additives | Low. | Low (prevention) | Minimum |
| Cylinder decoding | Medium | Medium/High | Medium (aggressive chemistry) |
| Mechanical (manual) | High. | High. | High (human factor) |
| Sandblast (shell) | High (requires removal of the GBC) | Maximum | Low (with the right technology) |
Cleaning of the intake system and EGR valves
In modern engines with an EGR, the gas is not only generated inside the cylinders, but also in the intake manifold. The EGR valve returns some of the exhaust gas to the fire, which reduces the combustion temperature and NOx emissions. However, the side effect is the rapid overgrowth of the soot intake ducts.
An EGR contaminated valve can jam open or closed, the first one will suffocate, the second one will detonate, and cleaning this assembly often solves the problems of unstable operation without having to climb inside the motor.
Use a special carburetor or throttle cleavers to clean the EGR valve. Do not use aggressive solvents that can damage the electrical part of the valve.
Intake manifolds are sometimes cleaned with a wet wash or ultrasonic bath (for removed parts), and it is also important to check the condition of the intake valves. Direct injection (GDI, TFSI) engines do not wash the valves, so the fuel on them grows very quickly and requires regular cleaning.
The intake cleaning procedure usually takes several hours, and after assembly, the throttle and EGR valve must be adapted using a diagnostic scanner, without which the engine may not work properly.
Prevention and proper care
The best way to control the pollution is to keep it out of the way, and that doesn't mean you just have to buy premium fuel, although the quality of gasoline or diesel is a huge part of it. It's more important to keep the oil change intervals. Old butter loses its detergent properties and begins to burn actively, creating a layer of sediments.
The operating mode can also be adjusted: periodic trips on the highway at high speeds help the engine to self-clean, high temperature and gas flow speed burn out light fractions of the carbon monoxide, this is especially true for diesel engines that need to regenerate the particulate filter.
- 🛢️ Change the oil more often than the regulations if the engine is operating in difficult conditions.
- ⛽ Only refuel at the checked gas stations of large networks.
- 🏎️ Give the engine load: once a week drive 20-30 km in dynamic mode.
- 🌡️ Watch the temperature regime, avoid overheating.
And good quality depositor additives can be a good prevention, and they work all the time, modifying the combustion process and keeping soot particles from sticking together into solid coke, but there's no wonder, because if the engine is worn out, the additives will only slow down the process.
Regular replacement of quality oil and periodic trips at high speeds is the best and cheap prevention of the formation of soda.
Frequently Asked Questions (FAQ)
Can I completely remove the stain without breaking the engine?
It's not entirely possible if the sediments are old and hard. Chemical decoking can remove 70-80% of the sediments and stir the rings, but perfect combustor cleanliness requires mechanical intervention or sandblasting to remove the block head.
Is the decoking dangerous for the catalyst?
Yes, it can be dangerous. When you burn out a lot of chemicals and dissolved carbon, you get a lot of active substances and particulate matter into the exhaust system, and this can clog the cells of the catalyst or particulate filter, and after the procedure, it is recommended to check the state of the exhaust system.
How often should I do the decoding?
As a preventive measure, it is enough to do a soft decoking (an additive to oil) every 20-30 thousand kilometers. Aggressive cleaning with filling into cylinders should be carried out only when symptoms appear (a drop in compression, oil consumption), but not more often than once every 100,000 km.
Will the engine be able to eat oil?
If the oil is consumed by the stained rings, then the decoying is likely to help, but if the oil caps are worn out or there is a production on the walls of the cylinders, then the chemistry will be useless and repairs will be needed.