The oil performs the function of lubricating the rubbing parts and mechanisms of the internal combustion engine system. With prolonged use, the lubricant loses its original properties and is subject to replacement. However, not all motorists know that before changing the oil, it is necessary to flush the engine.
Flushing the engine is a critical maintenance step that every car owner faces. Even if the engine of the car is operated directly from the car dealership using the same oil, after 100-120 thousand kilometers a large amount of deposits, sludge, scale and other contaminants will accumulate inside the engine.
All this negatively affects the patency of the oil channels in the engine, overheating of thorn steam and oil starvation in some engine cylinders is possible. All this will sooner or later lead to costly overhaul.
When is an engine flush necessary?
When purchasing a car, each owner must take care of flushing the engine system and filling in fresh engine oil. Moreover, this process is carried out by chemical means in cases where:
- The new owner of the vehicle plans to use engine fluid from another manufacturer.
- Poor quality lubricant has been used in the past.
- A major overhaul of the internal combustion engine system is being carried out.
- The engine is worn out and needs to be flushed to remove hard deposits and deposits.
- The properties of the oil deteriorate when working in turbocharged internal combustion engines. As a rule, in them the lubricant quickly exhausts its resource.
- Various deposits and debris penetrate the power unit, especially when it comes to the oil system line.
In other situations, you can use engine oil.
Basic engine flush questions
Most often, motorists are wondering whether it is necessary to flush the system when filling oil, if the composition to be filled remains the same or is completely similar to the previous one.
In this situation, the engine can not be flushed, because regardless of the manufacturer, the type and composition of the motor oil practically do not differ. If you use grease from another manufacturer, then it is recommended to fill before the replacement interval.
Even when using semi-synthetic and replacing it with synthetic fluid, there is no need to flush the motor. The composition of these oils are almost identical to each other.
What flushes the engine
There are many options for flushing engines, including:
- Diesel fuel (diesel fuel);
- Dimexide.
- New or flush oil.
- Various specialized means, chemical reagents.
- Engine cleaning during complex disassembly or accelerated technology.
Some methods are feasible only in car services, for example, in https://avantage-style.ru, others are applicable at home. Each driver chooses independently which of the listed options will suit him and his car.
How to flush the engine when changing the oil
A good way to clean your engine system is to use new oil to flush. To complete this procedure, you must purchase:
- car oil;
- oil filter.
Action steps:
First of all, mining is merged. To perform this process, you must warm up the engine to operating temperature and turn it off. At the same time, all remnants of the motor fluid should drain. For best results, it is recommended to carry out this work on a lift.
- After draining, the oil is changed and a new oil filter is installed.
- Next, you should turn on the engine and leave it to work for 15-20 minutes, or the car runs 300-500 kilometers.
- The oil is drained again, changed to a new, good one, on which it is supposed to operate the car further.
For several days, you should not overload the propulsion system, it is advisable to drive at medium speeds.
The next replacement is carried out upon reaching 5 thousand kilometers.
This flushing technique ensures that the internal combustion engine is safely cleaned of slag, oil residues and other contaminants. In this case, it is not necessary to use chemical reagents that can adversely affect the mechanisms of the internal combustion engine system.
The effect of such washing is achieved due to the presence of detergent additives in the composition of the oil. Answering the question of which oil to flush the engine with, we can say that any one that contains a large amount of detergent and dispersant additives is suitable for this.
Is it possible to flush the engine with diesel fuel?
The use of diesel fuel as a means for flushing the oil system has both minuses and pluses. This method has been used for a very long time, and may well be considered "grandfather".
The fact is that diesel fuel has excellent cleaning properties, which are an order of magnitude better than those of gasoline. In addition, it can lubricate the channels and ducts in the engine lubrication system. This effect of diesel fuel has due to the content of a large amount of sulfur.
The popularity of diesel fuel as a flush is due not only to its good properties, but also to the fact that in the past there was not much to choose from, and drivers used any suitable means at hand. However, diesel fuel shows good properties even in our time.
But despite all the positive qualities, diesel fuel also has several disadvantages. This is primarily due to the fact that there is the possibility of using low-quality diesel fuel.
Its components can adversely affect the oil pump by clogging its filter. That is, in some cases, such washing can do more harm than good. And if this is a new car with an injection power system, it is better to completely abandon the use of diesel fuel.
Flushing with dimexide
This tool has been used as a flush for the internal combustion engine of a car relatively recently. It is not used in its pure form, but exclusively together with the small, dissolving in it.
It is also important to consider that before using Dimexide, it is imperative to remove heavy sludge deposits, paint, etc. from the inside of the sump and valve cover.
This must be done due to the fact that dimexide will necessarily “raise” these deposits into suspension and the fine mesh of the oil receiver can be clogged with them.
Dimexide should be poured exclusively into a hot motor, since its flushing qualities appear only when it is hot. The flushing mixture with dimexide is prepared at the rate of 300 ml of liquid per 4 liters of oil.
The cheapest lubricant can be used, because. after mixing with dimexide, it is not suitable for reuse even in a lawn mower. The engine with the flooded flush should be allowed to run for 15-20 minutes, after which it should be replaced with a new oil and be sure to change the oil filter.
An engine oil change will not be complete if you do not remove all drops of used lubricant, which may contain dirt, sediment and even iron chips. Otherwise, the residues will inevitably mix with the new lubricant and will spoil its properties from the first day of operation. But it is worthwhile to understand that when flushing the engine, it is already it, and not the old oil, that can remain inside. And depending on the quality of work, the percentage of such remaining flushing is 5-20%. That is, with an engine capacity of 1.6 liters, up to 400 ml of flushing fluid can remain. Here you will definitely ask yourself which engine flush is better to use so as not to at least harm the car?
What flush is better to flush the engine?
The main goal when choosing a flush is to minimize the harm that fresh oil that has just been filled in can not do. Because when reacting with flushing components, various anti-corrosion and viscosity-resistant additives can lead to foaming, reduced lubricity and the appearance of an emulsion in the oil. The most common problem is a decrease in the viscosity of the oil, because it must change its density depending on the temperature regime. But a large volume of flushing fluid reduces viscosity, and if you filled in 5W-40, then there is a good chance to get 5W-30 according to the characteristics.
Among the most common flushing fluids are:
- Diesel fuel. This is a "folk" remedy that is not indicated in any specification for the car. Out of habit, drivers of old VAZs and Soviet cars wash the engine with it. This folk wisdom has been passed on to other motorists today, although basic knowledge says that diesel fuel is not the best option. It can corrode gaskets, oil seals, engine seals. In addition, it is not the cleanest liquid. It is more likely to stain engine parts, while the oil is changed just in time to make the circulating fluid in it cleaner.
- Washing liquid. Quite light in composition, it can greatly dilute the oil if too much is left inside. Recommended only for experienced pros who know how to "kick out" all the liquid. For beginners who decide to do everything on their own, it’s not even worth arguing which engine flush is better. Without getting rid of any third-party liquids in the engine, except for native oil, it is naive to expect faithful service from it for many years.
- Five-minutes are chemical liquids that need to be poured into old oil before draining. It is necessary to fill them in and start the engine for five minutes so that the composition goes through all the details of the engine.
- Washing oil. Washing out the oil with oil may not be the cheapest option, but the safest for the design. Many are wondering which oil is best for flushing the engine - the most inexpensive or still specialized (the same as drained). If you are trying to save money, you can combine the two methods. First flush the engine with liquid, and then squeeze out the liquid with a part of the oil. Then not 5-10 percent of the flushing liquid will remain in the engine, but oil.
I remember I had a case. My car's engine was constantly overheating. As if not water in the cooling system flows, but fire. And the oil - rabbits do not multiply as quickly as it quickly turned black in me. Well, I think that's all - the engine is covered: do a major overhaul, or buy a new one. An, no. There were kind people who suggested what to do: flush the engine at the first oil change.
And business something - just nothing. In general, as they once helped me with good advice, so I will help you. Sit down comfortably, and I'll tell you:
- how to flush the engine when changing the oil;
- in what cases it is possible not to flush the engine;
- in which cases it is necessary to do so.
How to flush an engine when changing oil
1. Drain the used oil.
2. Fill in flushing. Ideal if you fill in the same one that you will use in the future, with the addition of detergent additives. But it can be pricey. If funds are limited, then we use a special flushing oil.
You need to pour as much as the motor requires for normal operation. For example, if the factory prescribes 3 liters, then three liters of oil must be poured for flushing.
3. Start the engine. Let the car stop, and it works for 10-15 minutes. Periodically press on the gas pedal to pick up all the debris from the bins.
4. When the allotted time has passed, turn off the motor. Drain the flushing oil and refill with fresh oil.
All. Now you can hit the road.
You need to flush the engine after about every third oil change. If this is not done, what was described at the beginning will happen. And this is at best. At worst, the engine will definitely come to an end. But do not rush to take advice ...
When to and when not to flush the engine
There are a couple more nuances.
1. You can not flush the engine if you bought it new and constantly use the same oil (expensive with detergent additives).
2. If you bought a used car, then at the first MOT, flush the engine (it is not known what kind of oil the previous owner used). After that, fill in only the same products from trusted manufacturers. Preferably with detergent additives.
Summarize:
If you bought a new car, then you will never need to flush the engine if you use the same oil, and it is excellent and has detergent additives.
Flushing the engine when changing the oil is required if:
- you bought a used car;
- going to switch to another oil;
- or use low-quality products (in this case, we follow the advice: flush the engine after every third oil change).
Disputes on the topic of whether an engine flush is necessary before an oil change have been going on in automotive forums for a long time, and there is still no single solution on this matter. Supporters and opponents of this procedure have their own arguments and arguments, which both substantiate their own opinion, so it is clearly premature to expect such a discussion to end soon.
What happens to the oil when the engine is running
During the operation of the internal combustion engine, lubrication of rubbing parts is simply necessary. In addition to lubricating moving parts, oil also serves to cool them. However, the loads arising during the operation of the motor - mechanical, thermal, high pressure, exposure to burnt and unburned fuel particles, lead to the loss of oil characteristics, primarily to its oxidation. Oxidation products in the form of solid deposits appear in the most unexpected places, clog a variety of gaps and oil passages, which worsens the lubrication of the motor, adversely affecting its operation.
What foreign matter can enter the engine as a result of oil oxidation?
- Acids. The consequence of their appearance will be corrosion of metal parts and a change in the characteristics of the oil, due to the consumption of its alkaline additives to neutralize acids.
- Tars and tarry deposits - as a result of the polymerization of particles of unburned fuel and oil oxidation products.
- Carbonaceous deposits that form on heated surfaces.
Of these, it is worth noting:
- soot - the result of the destruction and polymerization of oil and fuel, as a rule, it is black. Due to its formation, the temperature regime of the motor is deteriorating;
- varnish, which is a thin layer of a substance formed during the polymerization of oil on heated surfaces, most often appears on the skirt and the inner surface of the piston, fingers and connecting rods. It reduces heat removal, which reduces the strength of parts, their wettability deteriorates;
- sludge, which is an emulsion formed from oil and insoluble, as well as resinous substances. It leads to an increase in its viscosity and a deterioration in lubrication characteristics.
Of course, the data presented do not cover all the processes that take place during the operation of the engine, but they give an idea of some of the transformations that occur during this.
Oil change - no alternative
The oil itself is destroyed during prolonged operation in extreme conditions and needs to be replaced. It is when replacing it that motorists often have a question - is it necessary or not to flush the engine before changing the oil? It is understood that its purpose is to remove oxidation products in order to restore the original characteristics of the motor.
If the issue of changing the oil is not objectionable to anyone, then flushing the engine during an oil change is extremely controversial - from complete rejection to mandatory implementation. There are also intermediate judgments and opinions that flushing can be done not with special fluids, but using cheaper mineral oils. And how can the engine be flushed during an oil change?
Engine flush methods
Now there are a large number of tools used to flush the internal combustion engine, and this action itself can be performed by several different methods.
Chemical
In this case, special liquids containing solvents are used - chemicals that act on a certain type of sediment. The agent intended for cleaning is poured into the engine, and it should work for several tens of minutes (the time is set by the manufacturer of the drug) at idle. After working off, everything is drained, and fresh oil is poured into the engine (along with filter replacement).
If the engine is sufficiently clean, i.e. Since such a procedure is performed regularly, it avoids the formation of soot, as well as other deposits in the internal combustion engine. However, if the motor is too dirty (slagging), then it is possible that the accumulated deposits that have gained mobility when performing such a flush will begin to fall off, enter the lubrication system, clogging the filter and oil lines. Even if the flushing fluid is completely drained, up to ten percent of it remains in the engine.
Soft wash
It is carried out in much the same way, only the flushing agent is added to the lubrication system in advance, when several hundred kilometers remain before replacement. Such a drug acts softer, does not have an additional effect on the oil, and deposits dissolve gradually. However, if carrying out such a flush on a clean engine gives the expected result, then how this will affect a contaminated engine is unknown. 
Full flush
In this case, the used oil is completely drained, the flushing oil is poured in, and the engine runs for several tens of minutes. After that, everything is drained, the remnants of the flush are forcibly removed from the engine, a new filter is installed and fresh oil is used.
Forced flush
For this, an external setting is used. Oil is drained from the engine, the filter is removed, and the motor is connected to the installation. The flushing liquid is forcibly, under air pressure, pumped through the lubrication system in the forward and reverse direction, all foreign particles are retained by the filter of the unit. The engine is not running. 
After the end of the procedure, a complete flush is carried out, as described above, to remove residual washing liquid. As a result of such washing, even heavily contaminated power units will be cleaned, however, the oil film on the parts will be removed and the motor will run “dry” for some time.
Why flushing is not needed
The processes occurring in the engine contribute to the formation of substances that impair the operation of the lubrication system. Flushing the motor should eliminate the consequences of such changes. However, such an operation is strongly opposed by many drivers for the following reasons:
- The use of flushing fluids leads to the fact that some of them remain in the lubrication system, which further causes a deterioration in the properties of the oil used.
- Modern high-quality oils contain the necessary set of additives that ensure the removal of foreign substances formed during operation. The use of modern lubricants ensures the regular operation of the engine and saves the driver from additional costs.
- It is possible to use cheaper mineral oil for flushing, fill it in and drive half the distance established by the regulations, and then replace it. This allows you to carry out a “soft” flush without exposing the engine to additional loads and without leaving aggressive substances in the lubrication system. After several such procedures, you can switch to high-quality oil.
- A possible option is a more frequent oil change, which will avoid its oxidation during operation.
The issue of flushing the engine is quite controversial and debatable. There is no consensus among drivers and service station specialists on this matter. The fact that foreign substances form in the engine during the operation of the car is beyond doubt, but how to get rid of them is up to everyone to decide for themselves.
A funny transformation in the minds of drivers has undergone such a simple procedure as flushing the engine when changing the oil. The historical experience of the fathers unequivocally said that it was necessary to flush. In the era of mineral oils of dubious quality (when there was no other besides them, at least in the USSR), it was simply impossible to do otherwise. However, the chemical industry does not stand still, and here we are using cool synthetics, which, according to the promises of manufacturers, will do everything in the motor itself. The engine flush was obstructed and was about to be thrown into the dustbin of automotive history, but it's too early to do so. Flushing the engine is, of course, an outdated procedure, but in some situations it may come in handy.
Filling flushing agent into the engine
When not to wash
Proponents of technological progress, in general, are right, if you use high-quality synthetic oil (in extreme cases, semi-synthetic) and change it at the time set by the manufacturer, or more often, then you don't need a flush. Of course, the engine will not be worse, but it will also be better. But you will pay for flushing and for a double replacement (or waste your time if you service the car yourself). If you want to pamper the engine and prolong its service life - slightly shorten the oil change interval - the benefits of this will be more than flushing.
Many people are concerned about the question - should you flush if you change the brand of oil? If it is the same level as what was filled earlier, for example, synthetics are changed to synthetics, then it is not necessary.
Therefore, in normal situations, flushing is not necessary. It's like with drugs - no one will take potent drugs just because they want to, for such a step, reasons are needed.
When to wash
However, there are situations when flushing the engine is highly desirable.
1. You bought a car from your hands and do not know its history. A used car is always a pig in a poke, but if the body, interior and chassis can at least be assessed visually, technical fluids are a big mystery. Whether the owner observed the replacement interval, whether he bought good oil - you cannot know this. There are cars with service books or receipts from stores, but this is rare and still does not give a guarantee (such things are very easy to fake). So for your own peace of mind, it is better to do the first oil change after purchase with flushing. If everything goes well, then you can no longer rinse.
2. When switching to a lower quality oil. If you pampered your engine with expensive oil, but then decided that it was redundant (for old engines designed and manufactured in the last century, expensive synthetics are not at all necessary), then when you lower the oil class, you need to flush the engine. The reason is that the old oil from the engine is not completely drained - if the plug is unscrewed, then 15% of waste remains in the system, if it is “sucked off” with a vacuum pump - 5-7%, but it is still there. And diluting mineral water with synthetics is not a good idea.
3. Antifreeze got into the oil. This is an emergency situation and here there is nowhere without flushing. It is necessary to completely wash out the remnants of antifreeze from the oil system, not forgetting to deal with the cause of the mixing of liquids. It may be necessary to flush twice to completely clean the sump and oil channels.
In the photo: in the engine
What and how to wash
There are several options for flushing the engine.
1. Compositions of the "five-minute" type. These are special bottles (similar ones are produced by Liqui Moly, ER, Hi-Gear, Comma, Lavr and others, costing from 200 to 500 rubles), which contain organic solvents. They need to be poured into the engine before changing the oil and let it idle for 5-10 minutes. The compositions are quite aggressive, they wash off the oil film, therefore, firstly, you should not fill them for a long time, and secondly, give the motor a heavy load. There is a washing effect, although if the motor has a lot of deposits, it is likely that part of the “bodyagi” will remain in the sump and not merge with the oil. In advanced cases, after using such compounds, it is better to change the oil twice, with a reduced interval. The compounds work, although in case of serious contamination of the motor, it is rather necessary to think not about flushing, but about.
2. flushing oil. Almost every oil manufacturer has a range of so-called flushing oils. In fact, this is a banal mineral water with a set of detergent additives. It must be poured into the engine and allowed to run at idle. The method is less aggressive, does not harm the motor, but it can wash out small old deposits. In addition, flushing oil is relatively inexpensive, so the price / quality ratio is a reasonable option.
In the photo: GM Dexos 2 5W30 engine oil and flushing Lukoil
3. New oil. You can rinse with the same oil that you are going to pour. This is a very good option, because a new portion of oil will not be mixed with an incomprehensible substance that did not merge after cleaning, and not with flushing oil, but with exactly the same composition, way and a little worked. Oil is usually washed in two passes, first the first batch is poured (it is possible to the minimum level) with a replacement, they drive for 2-3 days, then they make the final oil change and filter again. The method perfectly allows you to switch from a dubious "bodyagi" to high-quality oil without harm to the motor, but it is expensive, it turns out to change the oil and the filter needs to be changed twice in a row.
Despite all the controversy and controversy, the situation with flushing seems quite obvious. Owners of new cars who regularly undergo MOT don’t need it, it’s a waste of money, but when buying a used car, it makes sense to flush the oil at the first oil change, who knows what was poured into the engine before you. But then, switching to obviously good oil, you can forget about flushing again. If everything is already bad with the motor, then no flushing will help.
