What is engine decoking and when is it needed?
Nagar harms all the parts involved in the combustion process: it prevents the valves from fitting properly into their seats, the formation of sparks in spark plugs, it clogs the piston grooves, due to which the rings no longer adhere to the cylinder walls, which means that compression decreases, the gaps between the cylinders increase and pistons, leading to accelerated wear of the piston group. And most importantly, due to the occurrence of oil scraper rings, the waste of engine oil increases significantly, leading to even greater formation of deposits.
HOW TO UNDERSTAND THAT THE ENGINE NEED DECOXING
How to decoke piston rings without disassembling the engine
Of course, the best way to determine the presence of carbon deposits in the engine is to disassemble it. But the fact that there are deposits in the cylinders that need to be removed can also be understood by external signs, such as:
increased oil consumption (more than 1 liter per 1000 km);
gray (light blue) color of the exhaust, increasing it;
smoke from the crankcase exhaust pipe (breather);
detonation with a sharp press on the gas pedal;
reduction in engine power;
cold start problems.
However, there are nuances here. It should be understood that not always a large waste of oil will be the result of the occurrence of oil scraper rings. It can also be blamed on the general wear of the piston group: pistons and cylinders (sleeves), this is especially likely in engines with high mileage. It happens that oil enters the combustion chamber due to a malfunction of the turbine (if the car is equipped with a turbocharger). Any situation associated with an increase in the combustion temperature of the mixture can lead to an "oil burner": from incorrect chip tuning to a banal under-twisted candle. And the result of unauthorized combustion of engine oil will certainly be the formation of deposits - coking.
A common mistake in diagnostics is to limit yourself to measuring compression. This method is simple, affordable, and, it seems, as illustrative. However, due to the design of most four-stroke engines, the compression rings - which just ensure the tightness of the combustion chamber - lie in the grooves much less often (and later) than the oil scrapers, which are responsible for not getting oil from the crankcase. This means that the use of a compression gauge will not give an understanding of the need for decarbonization.
You can more accurately determine the cause of increased oil consumption using other diagnostic tools:
Cylinder air tightness analyzer (vacuum gauge). According to the principle of operation, this device is similar to a compression gauge (it is also screwed in instead of a spark plug), but consists of two pressure gauges and determines the maximum vacuum in the cylinder and the residual (parasitic) vacuum, so you can get information about the condition of the rings.
Endoscope. A remote chamber in a sealed housing allows you to inspect the interior of the combustion chamber and visually, but without disassembling the engine, determine the presence of deposits.
HOW TO COX ENGINE
Decarbonization of the engine, the better to do: the best means to solve the problem
Let's assume that the above methods, with varying degrees of probability, have established the presence of deposits that led to the occurrence of oil scraper rings. In order to decoke them, there are several ways:
Mechanical. Open the engine: remove the cylinder head, pan, remove the pistons, clean them with sandpaper and / or chemicals: kerosene, acetone, carb cleaners. The most effective, but certainly costly and time-consuming way.
With the help of liquid formulations. Special preparations are poured into a warm engine, into each cylinder, through the spark plug hole, and kept there for several minutes (usually 20-30), after which the engine is started. Pros: liquid decarbonizer softens carbon deposits, and it burns out in the chambers without harming the catalyst. Cons: the liquid composition cleans the bottom of the piston best, penetrate further into the grooves of the compression, and even more so, oil scraper rings, rarely even on in-line engines, and on V-shaped and boxer such tools are practically useless.
With the help of foam. The principle of using foam decarbonizers is identical to liquid ones, with the difference that the penetrating ability of foam is much higher than that of liquids. Foam quite effectively washes not only the combustion chamber, but part of the intake manifold, where deposits also accumulate.
The use of special additives in oil (washes). The agent is poured through the oil neck and used as a “five-minute” flush, only for 20-30 minutes, and not at idle, but at medium engine speeds. The advantages of the method are obvious: due to circulation under pressure through the working oil channels of the engine, flushing effectively cleans places that are hard to reach for static compositions.
The choice of means for decoking the engine depends on the parameters of the engine, the degree of contamination and, to a certain extent, on the financial capabilities of the car owner. In any case, after using any drug, it is imperative to change the engine oil and filter, and sometimes the spark plugs.
Today, when the choice of means for decarbonization
in the trading network is quite large, it is not recommended to use folk remedies from the past. For example, dimexide (a medical antibacterial drug), which is so aggressive that it can wash off paint from the oil pan, which will inevitably lead to clogging of oil channels, or a mixture of hydroperite with water, the use of which is not only ineffective, but also, if handled carelessly, is fraught with engine hydraulic shock.
And although most of the drugs sold are supplied with instructions and are designed for a wide range of motorists, if you are not confident in your abilities, do not risk it, save money by entrusting the engine decoking to professionals. For example, station specialists