The question of the need to wash the engine compartment and the car engine itself under high pressure is inevitably asked by almost every car owner during the operation of the vehicle. The reason for concern is not only the unsightly appearance of the engine and the rest of the space under the hood, but also worries about the overall performance of contaminated components and assemblies.

The process of gradual formation of layers of dirt and salts in the space under the hood is especially relevant all year round. Leaks of oil and other technical fluids become inevitable, as well as banal dirt penetrating from the outside into an unpressurized engine compartment. The further material of the article is aimed at helping the reader to understand all the pros and cons of washing the engine with Karcher.

The most accessible and common option is cleaning the engine with professional car washes, which actively and widely use Karcher equipment in their arsenal. For such a procedure, any Karcher with a gasoline engine, Karcher with a diesel engine or Karcher with an asynchronous motor is suitable.

You can also wash the engine yourself, especially if you have personal access to such equipment. Before starting the process, it is imperative to know certain nuances associated with cleaning a car engine from dirt.

Supporters and opponents of this method of washing the power unit were divided into two opposing camps.

Arguments for"

Among car owners who advocate the need for cleaning, there is an opinion that deposits and pollution can really shorten the life of the power unit and impair the health of other associated elements, so that periodic cleaning of operating mechanisms becomes a necessary procedure.

• a heavily contaminated motor demonstrates a deterioration in heat transfer;
• the risk of ignition of spilled liquids in the engine compartment increases;
• potentially there is a deterioration in the power characteristics of the unit;
• likely to increase fuel consumption;
• current leakage may occur;
• the power unit may begin to work less stably;
• the visual detection of leaks and other malfunctions becomes more difficult, which are noticeably less noticeable on a dirty one;
• there is a hit of harmful technical fluids evaporating on a hot engine into the air ducts and their penetration into the cabin;

Arguments against"

Other motorists argue that washing the engine compartment, especially with a Karcher, can only harm the car, and dirt deposits do not pose any significant threat to the motor and other components. The above arguments of supporters of regular washing are only suitable for very heavily contaminated units as a result of an emergency malfunction or individual operation features.

• the car after such a wash with Karcher very often does not start;
• electrical connectors protected by rubber seals are not a guarantee of complete tightness against ingress of high-pressure water from the washing machine;
• the engine control unit located in the engine compartment may fail partially or completely;
• failure of various expensive electrical equipment;
• flooding spark plugs and candle wells with water;
• high probability of short circuit;
• engine water hammer due to water entering the cylinders through the ventilation ducts or inlet pipe;
• accelerated corrosion of joints and welds in the engine compartment;
• rubber and plastic sealing joints and insulation become unusable after contact with aggressive detergents;

Each argument above by car owners has a well-deserved right to exist, but let's turn to the recommendations of the automakers themselves. Car manufacturers emphasize that the recommended washing of the internal combustion engine and the engine compartment will be cleaning not in order to improve the appearance of the engine compartment and its characteristics, but a forced necessity.

• Severe contamination of the unit with automobile oil due to leakage of oil seals, oil lines and pipes.
• For diagnostics in order to detect aging of joints and rubber seals, leakage of technical fluids, etc.
• Before complex work on the overhaul of the power unit, which implies its disassembly, partial or complete dismantling of attachments, etc.
• Pre-sale preparation for placing the car on those trading floors where the cleanliness of the engine compartment is a must.

Based on all of the above information, we can conclude that it is not recommended at all to carry out the engine wash procedure without extreme necessity. Unscheduled cleaning of the power plant will be required only if the unit is heavily contaminated and the individual features of the operation of the vehicle require such regular washing.

Do it yourself or contact a specialist

If you are faced with the need to wash your car engine for various reasons, but do not have experience in implementing this process, then the best option would be to contact a professional car wash with the provision of this service or a service station.

Please note that the cleaning specialists are well aware of the process itself, they will correctly select and apply the necessary detergent chemical composition. An additional motivation for contacting a car wash is the great experience of the service employees and the potential availability of a wide selection of specialized detergents.

Another argument in favor of a car wash can be a simple saving of your free time. It is worth avoiding those car washes where the client is indicated that the service administration is not responsible for possible malfunctions after washing the engine.

Such advice does not mean at all that the presence of a Karcher at your personal disposal excludes the possibility of washing the engine properly on your own. Having decided on the decision to wash the engine yourself, it is also necessary to correctly select and purchase an engine cleaning agent, have some tools available, and comply with all the necessary conditions and recommendations regarding engine washing. This approach will help to avoid many mistakes and eliminate damage to the engine.

Mistakes in non-professional washing

• the use of detergents not intended for such a procedure (any shampoo, soap, dishwashing detergent, aggressive chemicals, etc.);
• use for washing the engine compartment of solvents, gasoline, kerosene, etc. (highest risk of fire);
• non-compliance with the temperature regime when washing the internal combustion engine (significant temperature changes should be avoided, which can lead to deformation of the cylinder head);
• washing with Karcher under high water pressure (the jet pierces the thermal insulation of the hood, breaks and deforms numerous fragile elements, etc.)
• insufficient protection of electrical connections, terminals and connectors. Ignoring the necessary rules for preparing the internal combustion engine for washing;
• lack of high-quality drying after cleaning the engine. Washing in winter;
• washing with the engine running;

What and how to wash the engine as safely as possible

If it became necessary to clean the engine with your own hands, then certain rules should be followed.

• Please note that you will have to work with auto chemicals, which requires increased accuracy and extra precautions (gloves will be needed, additional eye and respiratory protection may be necessary).
• The next step is the need to determine the nature of the contamination of the internal combustion engine. Those pollution that are caused by car oil caked and covered with a layer of dust cannot be washed off quickly. It is required to apply detergents for the time indicated in the accompanying instructions to soften this kind of pollution.

It is better to immediately abandon the decision to wash the engine under high water pressure with Karcher at the slightest doubt that this method is appropriate. It is quite possible to successfully apply and wash off the applied solution with a brush or a stream of water under normal pressure, but this will require additional time.

Choosing a detergent

Washing the internal combustion engine involves the use of only funds intended for this. The modern market offers a huge number of formulations in plastic and glass containers, aerosol cans, etc. This variety is supplied both in finished form and in the form of concentrates and gels that require dilution in the specified proportions.

Read the instructions carefully and try to use only products from trusted manufacturers, beingware of fakes.

Most of these compositions are universal and are designed to combat a wide range of contaminants, but there are also narrowly targeted agents. The main selection criteria are: minimizing the impact on rubber and plastic elements, the level of toxicity, packaging and price. You should not buy both the most affordable funds and overpay for expensive ones. It is better to opt for products of the middle price range.

1. Carry out the dismantling of all protective and decorative plastic parts and screens accessible for removal;
2. Be sure to seal all the necessary information labels and plates on the tanks, panels and other body elements;
3. The engine temperature before washing should not be lower or higher than 40-50 degrees. On a heated internal combustion engine, detergent compositions will evaporate very quickly, and on a cold one, their effectiveness will not be able to fully manifest itself. The water itself during washing should have a similar temperature, close to the recommended temperature of the internal combustion engine;
4. All elements of air intakes, connectors and terminals, the battery itself, car alarm elements and other regular and non-standard electrical equipment must be carefully sealed and protected from water. For this, adhesive tape and polyethylene are perfect;

Starting to wash the engine

1. Apply the required coat of a specially formulated cleaning chemical to the engine. This can be done with a brush on open surfaces, and the composition is applied to hard-to-reach places with a sprayer. Follow the instructions for use and wait after application for the amount of time indicated in the instructions.
2. Do not rush to immediately wash off the applied composition. Make sure that the thickest layers of dirt have had time to sag in all places. Try not to raise the pressure to 100-150 bar during the flushing process, but use the minimum necessary water pressure for this. After the final wash, evaluate the result obtained, if necessary, the procedure can be repeated;
3. The most important procedure is the need to dry the engine from moisture. This is done using pressurized air from a compressor. First of all, and very carefully, we dry the generator and starter, blow out the ignition coils and all available elements of the electrical automotive wiring.
4. The final stage of engine washing is a thorough washing of the entire car body, which is necessary for the final removal of all chemical compounds from surfaces;

If water gets on electrical equipment

The main common troubles that car owners may encounter after washing the engine compartment are:

• car won't start
• machine troit
• car twitches
• float speed
• oil pressure light on
• lit "check"

Let's look at the possible causes and solutions for each individual malfunction in more detail.

If everything is dried and connected, the battery and its terminals are in order and tightened, the starter turns and the fuel pump pumps, but the car does not start after washing, then you should once again pay attention to the ignition system.

• In those machines that structurally have a distributor, it will be necessary to remove water from under its cover by blowing and wiping dry. Next, we wipe all the armored wires, unscrew and inspect the candles, dry the candle wells.
• If the car has a distributorless ignition system and has separate coils for each cylinder, then all of them will have to be removed and dried. The rest of the steps are similar to working with the distributor option. The main rule is to purge and dry all available wires in the engine compartment, because no one is immune from imperceptible damage to their insulation.
• "Tripling" is usually called failures in the operation of the internal combustion engine. During such failures, one of the cylinders ceases to function normally. The driver immediately feels an increase in the amplitude of the motor and a constant strong vibration. In the mode of various revolutions and at idle, the engine runs with gaps and dips. This behavior of the machine is often due to similar reasons indicated in the first paragraph. We carefully inspect the armored wires and candles, dry the candle wells.
• When driving, the car twitches noticeably, there is an increase in fuel consumption and a drop in power. If the techniques described above did not help normalize the operation of the internal combustion engine, then there may be problems with the engine sensors. They may occur due to the fact that the alkaline shampoo in the washing process disabled them.
• Floating speed indicates that after washing there were problems with the throttle or throttle position sensor. These elements require cleaning and drying, and it is also advisable to reboot by resetting the terminals for 10-15 minutes.
• The oil pressure light on the dashboard may come on for a number of reasons. The first is that the same water gets on the oil pressure sensor and its contacts, which are very often located directly under the oil filter. The second reason may be the already familiar water ingress into the candle wells. It is treated by obligatory drying and / or replacement of failed parts.
• The "check engine" warning light, simply called "check" by motorists, is a clear indicator of a malfunction. Such a signal on the instrument panel appears as a result of errors and malfunctions in the operation of the internal combustion engine, which are recorded by numerous sensors, but it does not carry any specific information. Only reading the indicated engine errors from the computer memory with a special scanner at a service station will help localize the problem.

After washing the engine compartment, especially with Karcher, the sensors and their connectors are subjected to intense contact with detergent and water, so any failure in the operation of the engine itself or only the sensor will cause a "check". Sometimes the problem goes away on its own as the contacts dry completely or the malfunction is fixed. In some cases, the same reset of the battery terminals for a few minutes helps, which allows you to reset the error.

In the dry matter

From all the above material, a number of quite obvious conclusions can be drawn.

• Keeping the engine compartment in perfect cleanliness is not a paramount necessity for a car, and washing the engine should be done only when it is impossible to do without this procedure.
• Try to avoid non-professional washing of the engine with Karcher high-pressure cleaners, and if such a technique is used, then the water pressure should be minimal.
• The correct selection of detergent chemicals for the engine is an important step that should be given increased attention.
• Before washing the engine, it is worthwhile to carefully prepare and protect the connectors and contacts from water.
• Self-washing the engine is not as easy and simple a procedure as it might seem at first glance.
• It is recommended to wash the engine only at specialized service stations and service stations.

We hope that this article has fully helped our readers find answers to all their questions regarding washing the engine compartment and the power unit. All serviceable and clean engines. Good luck on the roads!

Read also

How to choose the best external engine cleaner to effectively remove engine oil and dirt from surfaces. Engine cleaner test, recommendations.

An article about high-pressure mini-washers - how to wash a car with a mini-washer, selection criteria and operating rules. At the end of the article - a video about choosing a home mini sink.

The content of the article:

Cleaning your car with a pressure washer is a good way to keep it clean. Most owners are sensitive to the appearance of their cars and are ready to spend time washing and waxing the body, polishing the headlights, and putting things in order inside. On the other hand, with too much of a busy life schedule, it seems like a tedious task, and a quick 10-minute walk through an automated car wash once a month is all you can afford.

Whether you wash your car infrequently or once a week if you want to do it quickly, using a high pressure car wash is a smart and efficient way to clean up your car. If you are worried about ruining your paint with strong water pressure, know that there is a safe working procedure. We will tell you how to choose and use such a device - it's easier than you might think.

Step 1. Choose the minisink that suits your needs

When washing a car, it is very important to use a machine with the appropriate power. Parameters such as PSI (working pressure) and GPM (water flow) are important here. The first is created by pomp, measured in pounds per square inch (PSI - short for "pound-force per square inch"), as well as in bars, pascals or kilograms per square centimeter.
The higher it is, the stronger the water pressure from the spray nozzle will be.

The second indicator will tell us about the amount of liquid used by the device per unit of time. It is usually measured in gallons per minute (hence the name GPM - Gallons Per Minute). In different markets, it may sound like LPM or LPH, reporting the consumption of a certain number of liters per minute or hour. The higher the numbers that define it, the more generous the flow of water will wash your car.

You may also encounter such a parameter as "cleaning units" - Cleaning Units. This is a kind of unified indicator of the effectiveness of your device. It is measured by the formula PSI x GPM = Cleaning Units. It will look like this: 1500 psi x 2 GPM = 3000 CU (as a rule, 1900-2800 CU is enough to wash a more or less dirty car).

Note: A pressure washer is much more efficient than a garden hose and uses less water. You can purchase both electric and petrol/diesel units.

The latter have enhanced cleaning capabilities and can be used away from a source of electricity, but require fuel costs, and are also heavy and too powerful for light tasks like washing an ordinary city car. In order to avoid damaging the delicate paint, it is better to use an electric machine set at a not too high pressure.

Advice: 80-130 bar (1200-1900 PSI) in everyday life is usually sufficient, and at this pressure you do not have to worry about damaging the paintwork. As for water consumption, experts recommend sticking to 1.4-1.6 GPM.

Step 2: Choose the right nozzle for your application

There are a number of nozzles of various types and sizes. It is very important to choose the right nozzles in order to wash your car efficiently and quickly without damaging the paint. Water flows evenly and is easily distributed over the treated surface, but the "beam" can be adjusted. Narrow covers a smaller area but with more pressure. Wider ones - on the contrary: the area is larger, the pressure is less.

Advice: it is best to buy a device with an adjustable "on the fly" jet - so you can not waste time changing nozzles and process different parts of the machine with more or less heavy pollution faster.

Step 3. Choose the right place and time for washing

It is very important to clean the machine away from other vehicles or objects that you do not want to wet or destroy with a powerful jet of water. When using an electric pressure washer, make sure you have access to a moisture-proof work outlet.

Note A: Not all devices can be used with extension cords. Make sure you always have access to a suitable outlet, otherwise you should get a fuel version of the car wash - it is heavy, but allows you to work without electricity.

Some models are equipped with wheels for easy transportation - look into this if you are not attracted to regular weightlifting.

Advice: never wash your car near chemical plants, coal mines, highways with constantly high traffic and similar places with a lot of dust, particulate matter, chemicals and other elements that can nullify your efforts, and in the worst case, damage your car .

Avoid close gatherings of birds - their excrement will ruin your work and mood. Do not work in hot sun or strong wind. Do not use detergents near water bodies and on grass - take care of nature.

Before using any car cleaning products, be sure to read the instructions for the car and the high pressure unit. Rinse the car by spraying water in a wide shower to wet the surface and get rid of dust and debris. In addition, it will help you test the minisink, get comfortable with the controls and adjust the settings to your liking.

Materials needed: high pressure washer with nozzle set (if no adjustable nozzle is available), water supply, socket or fuel.

Advice: Make sure all windows, doors, and trunk are closed to avoid flooding the inside of the car.

Carry out pre-cleaning

• connect the device to a power source;
• fix the nozzle at the water outlet;
• set the desired parameters of pressure / water flow;
• stand 1.5-2 meters from the car;
• turn on the unit, spray some water on the ground, checking the pressure;
• rinse the car from top to bottom, front to back.

Note: make sure to wash the wheels and all body parts. You may need to adjust the water pressure and move closer to remove any dirt in hard to reach areas. Always try to direct the jet at an angle to the surface to be treated to avoid scratches.

Apply detergent

Most high-pressure cleaners have special compartments for pouring detergents. Make sure you are using products that are suitable for your vehicle. Don't be tempted by low-priced dishwashing liquid, shampoo, laundry detergent, or soap - they will ruin paint, dissolve wax, and make your car look worse over time.

Note: Detergents are usually sold as ready-made liquids, powders or concentrates. Carefully read the instructions for their use - some will have to be diluted with water before applying to the car. The manufacturer will tell you the best ratio of water and their product. Stir the mixture thoroughly after dilution.

Necessary materials:

• high pressure washer;
• detergent;
• water;
• a bucket for diluting concentrated detergent;
• cloth, soft sponge, brush (optional, but better to have on hand).

Advice: Many will want to protect their airways, hands and clothing. Think about how you can do it.

Fill the special compartment of the pressure washer with the prepared detergent.

Reconfigure the unit to spray detergent instead of water. Start at the top of the car and work your way down. You can treat only heavily soiled parts or the entire machine. Let the detergent work to dissolve the dirt (usually takes about five minutes), but don't let it dry or you'll be left with stains.

Advice: if there is no reservoir for special equipment, apply the liquid manually in any way you like - with a cloth, sponge (without pressure) or a spray bottle (you can make it from a small plastic bottle with small holes in the cap).

Rinse the chemical from the surface of the car

No special skills are required here, just follow the rules: use clean water and wash off the chemicals in the order in which they were applied. When working near chipped paint, stickers, mirrors and other fragile parts, always reduce the spray pressure.

Necessary materials:

• high pressure washer;
• clean water in large quantities;
• towel, soft cloth, napkins (optional).

It's a good idea to hold the guide tube at a 45 degree angle while rinsing the machine from top to bottom. Don't forget to switch the machine to water instead of dispensing from the wash tank. Depending on your preference, you can use a towel or soft cloth to dry the car after rinsing with clean water.

Advice: at the end of the work, never wash your hands and feet with a jet from a mini-washer! It comes out under high pressure - they can tear the meat from the bones. The last thing you need is a trip to the emergency room.

That's it - you have successfully freshened up your car, improving its appearance and saving money on a car service. Regular washing with such a machine is not only considered a quick and effective way to increase the visual appeal of your car, but also can extend its life.

These units are categorized as "multipurpose cleaning machines". Eminent manufacturers, as a rule, offer them in a wide range and, as the price of the device increases, they increase the range of its capabilities.

All pressure washers are divided into two large groups - domestic and professional.

The main parameters of conventional car washes:

• duration of continuous work no more than 2 hours;
• interchangeable nozzles;
• pressure 20-150 bar;
• mains voltage 220 volts;
• most parts are made of plastic.

Features of professional car washes:

• the duration of continuous operation is not limited;
• adjustable nozzles and spray direction;
• pressure up to 1500 atmospheres;
• voltage up to 380 V;
• important details are made of metal.

It is worth paying attention to the length of the hose (the longer the better) and the pump, or rather, the material from which it is made. In inexpensive devices, it is usually made of plastic. This limits the machine's ability to operate for long hours without shutting down. Professional car washes are usually equipped with metal pumps.

You can choose additional options like water heating (for quick removal of frozen dirt, cold-water resistant oils and grease, comfortable car washing in cold weather) or the Total Stop function (the jet will disappear as soon as you release the “gun” handle). Not the most necessary things, but their presence will greatly facilitate the work. It is also worth buying a water filter (preferably reusable) - it will extend the life of the sink for several years.

Is it worth it to spend money on a mini-wash?

A caring owner washes his car at intervals of 2-3 weeks, regardless of the season. The car is constantly exposed not only to typical dirt, but also to direct sunlight, acid rain, salt through the air and snow, the sticking of midges, bird excrement and other debris, and often all of these.

Some contaminants are extremely aggressive: they can damage not only the paintwork, but also the chassis, body panels and other parts of the car. The car loses its fresh look and quickly rusts. In addition, dirt stuck to the bottom of the body creates more drag, which leads to increased fuel consumption (and money from your pocket).

Therefore, regular car washing is not just a matter of visual aesthetics. Not all rubbish is washed off with a sponge and a bucket of soapy water, so you have to resort to the services of car services. With a mini pressure washer you will be able to do this with minimal effort, at no extra cost and in no time.

In addition to the main purpose, this device will make it easier for you to take care of the pool, veranda, garage, fence, garden paths and benches - a zealous homeowner will find many areas of application for such a useful device in the household.

Video about choosing a home mini sink:

In order to qualitatively wash the car with the help of a mini-car wash, it is necessary to follow a certain technology, as well as to use detergents correctly. Therefore, we decided to prepare for you a small guide with a detailed description of this procedure, as well as some useful tips.

1 What will help us in the fight against dirt?

We note right away that our task is not just to wash off the dirt from the body, but to get the same result as in a professional car wash. For this we need:

• Karcher himself - this is how motorists call any car washes, regardless of the brand and country of manufacture;
• active foam, for example, you can use Karcher RM 806;
• soft napkin;
• wax protective agent;
• sash for windows.

For car enthusiasts, the Karcher brand of car washes has long been a household name and applies to all devices.

You can also purchase a plastic cleaner separately. But if you don’t have these detergents, it doesn’t matter, active foam will also do a good job of removing dirt.

2 Washing technology, or how to avoid stains?

Before you start washing, you need to prepare a high-pressure car wash, i.e. connect it to communications - electricity and water supply. To do this, the water supply must have a special fitting to which you will connect the hose. True, some models of mini-sinks can take water from barrels, cans, or even reservoirs. In this case, you just need to lower the supply hose into the water source.

Then you need to connect the high pressure hose to the foam nozzle. In the "plug'n'clean" tank, which is connected to the nozzle, you need to pour the foam. Keep in mind that the foam is sold in a concentrated form, so it must be diluted with water in the ratio indicated on the package. When all the hoses are connected to the machine, you can turn on the sink and start washing.

If you have separate products for discs and plastic surfaces, apply them to the stained areas. To do this, you can use a conventional sprayer. While the chemistry reacts with dirt, we proceed to the main part of the work - contactless car washing.

Many car enthusiasts make the mistake of starting washing by soaking and removing the main dirt. If you want to achieve a perfectly clean surface without streaks, you must follow the technology from start to finish. In particular, the foam should be applied to dry dirt, as a result of which it reacts better.

It is necessary to apply the composition in horizontal movements, from bottom to top, but not vice versa. This is important because the bottom strip reacts with the dirt to keep the top strip of foam from dripping down. This not only saves money, but also improves the quality of washing. Keep in mind that the foam strips should overlap each other slightly during application, due to this, there will be no untreated areas on the surface.

Pay attention to the concentration of the solution: if it is too low, a precipitate will fall on the surface of the body. Determine the concentration yourself "by eye" so that the foam is thick enough.

An important point is the time of the action of the foam on the dirt: if you wash off the detergent too early, it will not have time to react, respectively, the dirt will be removed poorly. If the foam is overexposed, then the "raised" dirt will begin to fall on the body in the form of sediment, which will subsequently lead to the formation of stains. Therefore, it should be on the surface of the body for 4-5 minutes.

Wash off the foam with a high-pressure jet of clean water. We start with the wheels, and also pay maximum attention to the wheel arches. Then we rinse the car in the same sequence in which the foam was applied - first we clean the thresholds, then the doors, fenders and windows, and lastly the roof. Don't forget to wash your rear-view mirrors as well. We drive the jet, like foam, with horizontal movements, slightly overlapping each lower clean strip.

Pay attention to areas under numbers, moldings and other hard-to-reach places where dirt usually gets clogged. If you wash them poorly, then dirty streaks may appear under them. . To achieve the best result, the car needs to be rinsed again. Now we direct the jet from top to bottom, i.e. I wash the body with vertical stripes that also overlap each other.

Now you need to apply a protective compound, for example, RM 824 is a wax with an intense water-repellent effect. Keep in mind that the composition is applied manually with a spray gun to all surfaces of the body, except for glass and mirrors. Before use, be sure to dilute the product with water according to the instructions on the package, for example, RM 824 is diluted in a ratio of 1:9.

A few minutes later, after waxing the surface, turn on the device and wash off the protective coating with a clean water jet under high pressure. The body is rinsed from wax in the same way as from foam, the only thing is that the jet must be directed from a close distance from the surface of the car - about 10 cm.

When working with the gun close to the body, hold the high pressure hose with your other hand so that it does not damage the car's paintwork.

This completes the work with Karcher. Now you need to take the squeegee and use it to remove water from the surface of the car. After that, take a dry cloth and wipe the car with your own hands. As a result, there will be no streaks or traces of water drops on the surface.

To wash your car with Karcher at home always gives the same result as professional car washes, follow these recommendations:

• do not wash the car in the sun, as shampoo and other chemicals will dry out quickly, not having time to react with dirt;
• for the same reason, do not start washing the car immediately after the trip - let it cool down. If this is not possible, start work with the doors, then go to the wings and roof, and only lastly apply foam to the hood so that it has time to cool a little;
• if the car body is wet after rain, let it dry;
• you should not save on auto chemicals, since cheap shampoos are unlikely to allow you to achieve a good result;
• do not use ordinary shampoos to wash the car - special auto chemicals are required for high-pressure machines.

That, in fact, is all you need to know in order to properly wash your car with a mini-car wash or Karcher. The only thing, do not forget about safety - active foam, falling on concrete, forms a slippery surface, so try to immediately wash it off the area around the car. Also, make sure that the washer hoses do not roll under your feet.