How to choose flushing oil and engine flushing fluids

With long-term operation of the engine on one oil, if the replacement intervals are not observed, as well as after buying a used car, when not only the replacement intervals, but even the oil brand are often unknown, it makes sense to resort to the so-called flushing. These are special oils and fluids with pronounced detergent characteristics that can dissolve soft deposits on the walls of the engine and effectively remove them from the system when changing the oil.

how to choose flushing oil


We recommend reading articles from an expert on the choice of engine oil and the secrets of choosing an oil filter.

The best manufacturers of flushing oils and fluids

Flushing the engine is a very important task. In order to avoid the appearance of scoring on the cylinder walls, as well as clogging the oil receiver mesh with large pieces of oil sludge, preference should be given to high-quality products from well-known brands:

  1. Liqui moly;

  2. Mannol;

  3. Mobli 1;

  4. Wynns;

  5. Castrol;

You should also pay attention to the reviews of users who have tested specific products on their car and made the appropriate conclusions about the performance. You can find them on the Internet at specialized forums dedicated to engine oils and car operation in domestic conditions.

Types of flushing oils and technical fluids

Traditional flushing oils

Traditional flushing oils

They are mineral base oils with a powerful detergent package. They are poured into the engine and used in it for 100-200 kilometers in a gentle mode of operation. During operation, they act on deposits, gently washing and removing them from the system.


  • Ease of operation;

  • Inexpensive;

  • Compatible with many types of cars;


  • Not suitable for modern direct inlet engines requiring very thin oil for correct operation (0w20, 5w30);

  • They are not able to completely clean the engine in one procedure;

Long-term flushing of the oil system


They are special liquids containing a powerful cleaning additive package. They are added to the used oil 150-200 kilometers before its replacement. They are very good at cleaning the engine from old deposits and oil sludge.


  • Inexpensive;

  • Do not change the viscosity of the oil;

  • Safe for CPG;

  • They wash the engine well;


  • Roads;

  • Do not allow intense driving style and high revs;

  • Require compliance with the operating instructions;

Five-minute flushes

Liqui Moly Engine Flush bottle

Liquids containing a shock packet of detergents and antiwear additives. They are added to the car directly when changing the oil and assume idle operation for 5-10 minutes. Soft sludge is washed and harder sediments are liquefied, while fresh oil does the final job.


  • Even old and hardened deposits are perfectly washed away;

  • They are used both independently and in combination with long-term flushing;

  • Do not harm the engine;


  • Expensive enough;

  • It will not be possible to achieve complete drainage of the liquid, some part remains in the oil system;

  • Do not allow working revolutions and operation of the car, being poured into the system;

  • If the rules of use are not followed, they can lead to scuffing on the cylinder walls;

The main criteria for the selection of fluids for flushing the engine

oil selection criteria for engine flushing

The composition of the liquid and the manufacturer's recommendations for its use

In order to minimize the risk of damage to the engine during the flushing procedure, it is necessary to give preference to proven products from well-known manufacturers, and also follow all recommendations for its use.

  1. Flushing oil and long-term flushing for the engine should be filled strictly at a certain interval and operated exclusively in a certain mode;

  2. A five-minute flush is poured into oil warmed up to operating temperature, after which the car is started and allowed to idle for 10-20 minutes;

Composition and availability of a complete package of additives

Pay attention to the fact that the flushing oil or engine wash fluid contains not only a full range of detergent additives, but also effective antifriction and antiwear additives. The latter are needed in order to avoid the appearance of scoring on the cylinder walls and to make the flushing process as safe as possible.

Rinse or not?

Opinions among car mechanics on this issue vary. It is necessary to resort to the flushing procedure only if the motorist does not know in what mode the car was operated and what oil was poured into it. For this purpose, it is better to use high-quality long-term or five-minute washes from Liqui Moly and other well-known brands.

If the car is serviced in accordance with the regulations recommended by the manufacturer, and the oil change interval does not exceed 7-10 thousand kilometers, the use of flushing loses its meaning. In such a situation, experienced specialists recommend performing 2-3 oil changes with an interval reduced to 3-4 thousand kilometers, thus performing an impromptu flushing.


In the next article, we will reveal all the secrets of choosing a quality timing belt.

Attention! This material is the subjective opinion of the authors of the project and is not a purchase guide.

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