Starting the diesel engine in cold weather

Owners of diesel foreign cars know well that when starting the engine. car in cold weather, emergency situations, as they are commonly called, may well arise. So the advice of experts will be useful now, in the fall, and in the coming winter. Failure-free diesel starting is ensured by the minimum starting speed crankshaft(p/min). It is sharply reduced by element malfunctions standard system electric starter - battery, electrical wiring, starter. The cause of unsatisfactory cranking of the crankshaft can also be increased resistance to its rotation when starting the engine: the starting device overcomes the resistance of friction forces in kinematic pairs. Friction is influenced by several factors. For example, viscosity motor oil, which is determined by the initial quality of the used oil and timely replacement. An increased friction torque can also be caused by poor-quality diesel assembly (for example, when the gap in kinematic pairs is below the required value). In this case, the engine will usually overheat after starting.

The pressure and temperature of the mixture at the end of compression during the diesel start-up process will not improve the situation. So, if the operating compression mode is 4.0-4.5 MPa, then at startup it is in the range of 1.5-3.5 MPa. The temperature at the end of compression under operating conditions reaches 600-700 C, but at start-up it can be lower 380°C, i.e. below the auto-ignition temperature of the fuel. In swirl-chamber and pre-chamber diesel engines (the most common designs of automotive diesel engines), due to large heat losses, the mixture temperature at start-up will always be below the auto-ignition temperature (even at an intake air temperature of 20°C). Therefore, to start such diesel engines, electric glow plugs are used, which are installed in the vortex chamber or in the prechamber and ensure ignition of the injected fuel. Glow plugs come with an open spiral and a spiral placed inside a protective casing. Glow plugs are common closed type, and open ones are found only in Mercedes diesel engines of the old design. Closed-type glow plugs (pin plugs) are located inside a casing with a powdered filler (usually periclase), which is an electrical insulating material with high thermal conductivity. The casing material is incopel alloy. Heating time for pin spark plugs operating temperature(1000°C) depends on the design and heating element, it ranges from 7 to 60 s. For modern diesels spark plugs with the shortest heating time (about 7 s) are used, which varies depending on the engine temperature and environment. The machines protect the heating element of the candle from high voltage and current.

Pin glow plugs are installed in the combustion chamber so that the cone of the fuel jet only touches the hot end of its casing. To extend the service life of open spark plugs, it is necessary to install them in such a way that the jets of sprayed fuel do not touch the spiral. The heating time of the spark plugs to operating temperature must correspond electronic circuit control installed in the diesel engine. When glow plugs fail, they must be replaced with plugs with the same heating time, otherwise some or all of the plugs will not work (heat up). To improve starting in diesel engines with direct injection fuel at the inlet of the cylinder, air heating is used due to glow plugs located in the intake manifold and an electric torch heater. However, using more than one candle increases energy consumption and increases aerodynamic drag inlet pipe. Therefore, they are used to facilitate the start of diesel engines with direct fuel injection at temperatures not lower than -15°C; at a lower level, the intake air is heated by an electric torch heater. In some diesel engines with a divided combustion chamber, in addition to glow plugs installed in the vortex chamber or prechamber, air heater plugs in the air manifold are used to improve starting (for example, in the Toyota Hi-Ace). This uses more powerful rechargeable batteries. An electric torch heater is mounted in the diesel air manifold and heats the air by mixing it with combustion products created by the heater. One of the advantages of the heater is the ability to operate on diesel and other fuels (to improve starting, it is recommended to use flammable fuel). And the main disadvantage of electric torch heaters is that the driver does not receive information about the presence of a torch in the intake pipeline during the diesel engine start-up process. Failure of the heating plug or clogging of the fuel supply device will lead to a lack of ignition of the fuel in the intake manifold and poor starting of the diesel engine, but the driver will not know what caused it. At temperatures below -25°C, to facilitate diesel starting, flammable liquids are sometimes used, which are injected through the air manifold. Their use for diesel engines passenger cars undesirable. During such a start, the engine experiences severe loads, cracks appear on the pistons, liners and other parts quickly wear out. Diesel starting is significantly affected by mixture formation and fuel combustion at the time of start-up. Therefore, in winter, diesel engines use fuel with a lower viscosity than in summer. In addition, it has a lower pour point and flash point compared to summer diesel fuel. When operating diesel engines in winter, Opel recommends adding up to 10% gasoline to winter diesel fuel. Mixture formation in a diesel engine depends on the characteristics of the injection process. The main role in this is played by fuel burner. At bad work injector sprayer (fuel is not sprayed, but flows into in the form of a jet), starting the diesel engine is difficult, smoke increases. The flow of fuel from the nozzle in the form of a jet is accompanied by overheating of the piston, which leads to rapid wear its rings and burnout. Fuel ignition in a diesel engine is determined by its starting flow and the fuel injection advance angle to the top dead center. These characteristics are specified by adjusting the equipment on the stands and within the engine. Wear fuel pump, associated with the ingress of water and dirt into it, leads to a decrease in starting feed and poor starting. Wear piston group leads to a decrease in compression, which also impairs diesel starting. In case of severe wear, only the major renovation engine. The engine wears out most intensively when starting in cold weather, since the thickened oil does not provide sufficient lubrication of the kinematic pairs. Therefore, all the presenters foreign companies supply diesel cars, designed to work in cold climatic conditions, systems preheating diesel Pre-heater for 10-20 minutes. warms up the engine coolant to a temperature of 60-80°C. The liquid is forced through the engine by a water pump and warms it up. A warm engine has a reliable start and its service life increases. Some companies use heaters powered by a 220 V network. They are installed in a water or oil system(or both at once), and the liquid circulates due to free convection. Since the heat exchange is less intense than with heaters with forced convection, the engine is heated within 3-4 hours. If the car is parked, such a system is usually turned on all night.

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Passenger car configurations increasingly require installation diesel engine, which was previously used exclusively for freight transport. The diesel engine has a number of differences from gasoline engine V technically. The owner of a car with a diesel engine must know the rules of its operation, including in low temperature conditions. Starting a diesel engine in cold weather is not always possible without problems, especially if the car has not been properly prepared for winter.

How does a diesel engine behave in winter?

Gasoline engines are more resistant to frost than diesel engines, and this is largely due to the fuel itself. Diesel fuel ignites under high pressure, and compression is the main indicator that determines the presence or absence of difficulties starting the engine in winter. Even if the battery is fully charged, if the engine compression is low, you may have problems starting it.

The recommended compression for a diesel engine in winter conditions in the central region of Russia is about 25-30 atmospheres. Naturally, each engine has its own compression indicators that are sufficient for starting, but the following average values ​​can be given:

Considering that car manufacturers are trying their best to insulate the engine and fuel tank, For modern cars The above figures are not entirely relevant.

How to prepare a diesel engine for winter

We recommend reading:

The rules for preparing a diesel engine for operating conditions at low temperatures are aimed, first of all, at increasing compression. Before the cold starts, we should do the following:

If there is any doubt that the engine will operate stably at the expected temperature, you can cover the engine with a blanket or install pre-ignition.

What to do if a diesel engine does not start in winter

If the glow plugs are in good condition, they will help start the diesel engine in the cold season. Their task is to warm up the combustion chamber fuel mixture, and the driver must do it correctly. The shutdown of the glow plugs is indicated by the corresponding light on the dashboard and the relay clicks. Before starting the engine by turning the ignition key all the way, it is recommended to warm it up 3 times with glow plugs. For this:

1. We turn on the ignition and wait for the relay to click, indicating that the glow plugs have been turned off;
2. Turn off the ignition. After 20 seconds, turn on the ignition again and wait for a click;
3. Turn off the ignition. After 30 seconds, turn on the ignition again, and after the glow plug lamp goes out, immediately start the engine.

Also, to make it easier to start the engine in the cold season, you can use various “chemicals”:

• Superantigel that prevents fuel from freezing;
• Fuel dryer that prevents the formation of ice by removing moisture;
• Cetane plus, which increases the cetane number.

With the onset of cold weather, you can often see car enthusiasts trying to start their “ iron horses" And, if with gasoline big problems does not arise, then the owners diesel cars it's not easy.

How to start a diesel engine in cold weather - possible problems

Frost is not always the only culprit for the car not starting; other factors can also contribute to this:

• Not quality fuel.
• Unreliable battery.
• Candles are of poor quality.
• Faulty injector and starter.

Before the cold weather arrives, it is better to check the engine operation at a reliable workshop and change the oil to one suitable for low temperatures. It is necessary to achieve the recommended levels of indicators. So, for a diesel engine to start in cold weather, the battery voltage must be at least 12.5 V.

Methods for starting a diesel engine in cold weather

• If it didn’t start right away, don’t panic. By squeezing the gas pedal, we try to start the car with the starter. 10-15 seconds and take a break for 1-2 minutes to give the battery a rest. Then we try again. If it doesn’t start on the third try, we move on to another method. It’s not worth repeating this many times, otherwise the battery will eventually discharge or the starter’s performance will significantly deteriorate.
• "Lighting up." Used when the battery charge is low. To do this, you only need wires and a caring driver with his own running car. After starting, do not immediately turn off the ignition; you need to let the car run for a few minutes, and better time, For fully charged battery Then there will be no problems in the future.

• Another method for batteries. In this case, it must be removed and recharged at home. As you know, in cold weather a diesel engine requires more electricity to start and a battery that is even slightly discharged will lose its power faster. You can remove the battery and store it at home, but if you have to use the car every day, then this option is not the most convenient.
• Tow. Very dangerous way launcher, which is best used in the as a last resort. When using a pusher, sharp jerks will be inevitable, which in turn can lead to a rupture of the timing belt. And this will entail very expensive repairs.

• If possible, install an autonomous pre-heater. This system is installed in front of the fuel filter and will heat the fuel to working condition in a few minutes.
• Usage special additives and antigels. At low temperatures, diesel fuel thickens and a sediment or paraffin forms. When mixed with diesel, such products do not dissolve paraffin, but simply prevent it from growing. When deciding to use an additive, you should carefully read the label and remember that it must be poured into the tank at above-zero temperatures.

• “Old school” drivers, not trusting modern anti-gels, use kerosene. In practice the result is the same, kerosene is harmful fuel system does not apply. Only you can add it no more than 30% to the total volume of fuel (for 10 liters of diesel - 3 liters of kerosene).
• For vehicles with automatic transmission gear oil can be another problem. At severe frost it thickens significantly and also requires heating. But now oils are sold in abundance various brands just for the winter season and therefore there should be no problems here.
• What to do when the diesel fuel is already frozen? Here we will have to act on a larger scale. Having covered the car with a warm cover, a heat gun is placed under the bottom. You will have to wait until the engine temperature reaches at least 0 degrees. Some car enthusiasts light a fire under the bottom of the car, but this method is unsafe.

It is not always possible to park a car in a warm garage, and with the onset of cold weather, unpleasant “surprises” may await lovers of diesel cars. But high-quality fuel and a timely prepared car for winter significantly reduce the risk of being left without a car and having to walk to work in the morning.

The diesel engine is good because it consumes less fuel than gasoline. But one winter morning it may refuse to start, and then it’s not clear whether to be happy or not, because it doesn’t consume fuel, but it doesn’t drive either. Let's figure out why diesel doesn't start in cold weather and how to operate it correctly in winter.

Reasons why a diesel engine does not start

Actually, the reasons are still the same:

• fuel problems
• lack of compression

Other reasons have nothing to do with winter operation, since in warm weather it would not start either. But there are also some nuances here.

Serviceable diesel engine correct operation starts in any frost. Well, almost any time. I have no experience of operating a car in the far north, but in -30 frost the diesel engine starts easily.

What problems can arise with fuel in cold weather?

Let's start from afar. DT can be winter or summer. Depends on the paraffin content in its composition. Summer diesel fuel is guaranteed to work only at temperatures above -10 °C. If the temperature outside is lower, the paraffin thickens and the diesel fuel loses its fluidity, causing the fuel filter to clog. Have you ever seen a truck driving and driving, getting slower and slower, and then stopping altogether? This diesel fuel thickens, paraffin clogs the fuel filter and fuel does not enter the engine. This problem can be partially solved by heating fuel filter, but in severe frost the diesel fuel will harden while still in the tank.

In winter diesel fuel there is significantly less paraffin than in summer (paraffin is the basis of diesel fuel, it releases the most energy during combustion), in addition, special antigel additives are used that prevent diesel fuel from freezing.

You can also pour the antigel additive directly into the tank when refueling.

Here is a list of the most popular anti-gels today

Antigel diesel LIQUI MOLY Diesel Fliess-Fit, 0.15 l (1877)

Volume: 150 ml
Designed for temperature: -31 °C
Fuel volume: 50 l.

Super antigel for diesel fuel Hi-Gear -47C, HG3422 (for treating 90 liters of fuel). HG3422

Designed for temperatures: -47 °C
Fuel volume: 90 l.

Compression

If there is no compression, a diesel engine will never start. But this is not about mechanical damage which led to . This can lead to

• discharged battery,
• thick oil
• engine wear
• faulty wiring

Actually, the fuel burns when it reaches a certain temperature, this temperature is created at a certain pressure, when one of the above-described malfunctions appears, the air flows out of the chamber before the required pressure is created.

In any case, compression rings always allow air to pass through, even the most serviceable ones, even the damaged ones. And here the engine’s task is to create as much pressure as possible at TDC so that the diesel fuel ignites easily. So, than faster engine will rotate, the less air will have time to escape through the cracks.

This is where all the malfunctions appear - a discharged battery that cannot really spin the starter (you can’t tell by ear whether it’s oiling properly or too weakly), the compression is too low or the oil is a bit thick - again, it’s more difficult to turn over the engine. Or maybe the starter is faulty.

If the compression is weak, this can be easily checked by ruling out this malfunction. We unscrew the glow plugs and pour a spoonful of engine oil into each cylinder, screw the spark plugs back. The oil will spread throughout the combustion chamber and fill all the cracks. Compression will be higher than with a new engine. If after this the car does not start, it means something else is faulty.

If the engine oil is thick (the viscosity is incorrectly selected for winter operation), then it will be more difficult for the starter to crank the engine and spin it to the required speed for it to start.

A discharged battery or a faulty starter will also not spin the engine to normal speed, and all these factors taken together make starting a diesel engine in cold weather very problematic.

You can try to start the engine with a pushrod, but this also has its own problems - this will not work in a car with an automatic transmission, and even if there is snow and ice on the road, there will be no normal grip on the road and the car will simply skid. Another problem is that the timing belt may break when starting from the pushrod, as it will sharp jerk, when the car starts and can cut teeth.

Combustion of fuel

Before combustion, the diesel fuel must evaporate and turn into fine smoke. When the engine is warm, this is quite simple. But what to do when starting when the engine is cold? For this purpose, there are glow plugs, which evaporate cold fuel before ignition, thereby helping to start the engine. If the fuel is poorly atomized, the engine will puff and fart, but will not start. Therefore, it is worth paying attention to the performance of glow plugs.

These are, perhaps, all the reasons why a diesel engine does not start related to frost.

To solve these problems can be used preheaters type Webasto, which heat the engine through the cooling system, which eliminates several problems with starting - oil it immediately becomes less dense, the engine becomes warmed up and, accordingly, the piston-cylinder clearances decrease, which reduces air leaks from the combustion chamber, and the cooling system on many cars is connected to the fuel filter and heats it up, thereby preventing paraffin from settling in it. Plus a small bonus - at the same time the interior will heat up.

I think many residents of our northern country often faced frosts. This natural phenomenon affects many motorists who cannot start their iron horses at very high temperatures. low temperatures. This is especially true for already tired diesel engines.

So this week, an anticyclone unexpectedly arrived in my native Moscow, bringing with it temperatures below -20. About a third of the city started up, diesels and even worse, about 1/5 of all diesels.

On the first day of frost, I didn’t start either, on the thermometer in the morning the red liquid indicated a line somewhere around -25... Well, what can you do, I have to take my child to school, my wife to college, and drag my butt to work... . I dressed lightly, hoping to start the 4d68 tractor. Sneeze-puff tyr tyr did not start at all. He gave the child to his wife, and he himself, in summer boots and pants (at least he had put on a winter jacket), went to wait for the bus. Well, 30 minutes of standing in the cold, 40 minutes in an icy bus and all this without gloves did their job, I firmly decided to start my diesel engine at all costs the next morning...

I started by calling my clubmates and acquaintances to ask: “Can you light me up in the evening?” A couple of people agreed, one, thank God, is close to me and since he is a very good person, he decided to help me.

Returning to the house on a warm minibus, I began to wait for Vova, that very good person. Fortunately, he arrived promptly, and his wife took upon herself the issue of picking up the child from kindergarten.

In general, having smoked from his car, they began to oil the starter... sneeze puff, one pot grabs, the rest do nothing. There was no point in standing any further, given that lighting the cigarette does not provide enough energy to crank my diesel engine. We went to him for charging, then after reading the microbe forum we decided to buy ether, the so-called “easy start”. In one store it ran out in the morning, in another we found as many as 4 types of these cans. Well, having bought, in my opinion, the best one (Made in Belgium) we went back to my car. Yes, the salesman in the store said that you need to remove the + wire from the spark plugs so that the air vents don’t break. Well, we drove up, lit a cigarette, popped some air on the air, not a single pot caught. Vova went home, I went home to charge and warm up the battery.

In the evening I surfed the Internet a lot about the issue of starting a diesel engine in the cold, read everything I could and now I know several ways to start it, they will be discussed below.

Morning. -26, humidity 96%. I pulled out the spark plugs, checked their glow, placing their body against the - terminal of the battery and connecting the wire to + to give the voltage. One of the candles was dead, one was heating up quickly, one was slow and another 1 was original, its work seemed ideal to me and I took it as a standard for comparison with others. I pulled out 4 spare spark plugs from the trunk and checked them too. As a result, 3 original spark plugs were installed in the engine; I installed NGK D-Power on the 3rd pot, because... This pot has the lowest compression, so even with good spark plugs it’s unlikely to help the engine start. And I still have one NGK D-Power in reserve.

After that, I warmed up the spark plugs from click on to click off, pumped the pump on the fuel filter 5 times, warmed the spark plugs up again, pumped the air for 1 second straight into intake manifold for reliability.

I sat down, pressed the gas pedal point-blank, 3 revolutions of the engine (by the way, with the ether, the engine was spinning as if on a +5 street, i.e. quickly and clearly), after which the car immediately started up without any hiccups and even kept idle without my pressing slipper

So, this has been described as the easiest method for starting a diesel engine in the cold. Now about other methods:

1. The method of the greatest hemorrhoids.

Unscrew the candles, pour into each pot 1.5-2 cubes of the motor oil you use, but warm. Crank the engine 5-8 times, tighten the spark plugs, and go start it. In theory, this technology uses oil to increase compression. Why crank? Yes, so that the oil is distributed evenly throughout all the rings, so it will give a greater effect. The problem here is that if you don’t turn it enough times, the oil can stick to the spark plugs and they won’t give the proper warming effect.

2. The method is a little easier.

Everything is the same as in 1, only instead of oil you need to fill in warm and definitely winter diesel fuel, and not 1.5-2 cubes, but you can use a little more, about 3 cubes. There are no jambs here, the candles won’t be stained with anything, you just need to have a syringe and not be too lazy to unscrew the candles. True, this method will increase the compression much less than in method 1.

3. Direct action method.

Take a wire so that there is enough of it from the spark plugs to the + terminal of the battery. 5-10 presses are made on the fuel filter pump, after which the spark plugs are connected directly to the + battery, wait 10 seconds, then start it. This method guarantees that the fuel in the chambers/injectors will be very warm, which gives a greater chance of starting than the automatic spark plug warm-up system. But there is a problem - that you can burn the candles.

4. Method for the lazy.

Just the method of spraying ether into the intake manifold. I can add that if there really is a problem with the establishment, then you need to have a 2nd person, so that 1 person sits and starts it up, and the second one at the same time pumps the air into the inlet, but don’t overdo it, otherwise it will tear everything to hell, and then it’s all over you'll never start.

5. heating pad method.

The essence of the method is to warm up the fuel/engine. Option with water - take boiling water from home, preferably 5-10 liters, first heat the filter, pouring it with a thin stream or immersing it in boiling water. Then we warm up the engine, fuel frame, injection pump - pouring it in a thin stream.

Option with a burner - heat the filter and fuel frame with a burner. Be careful not to burn hoses or electrics!

Collective farmers' options are to heat the tank or install an electric stove on a tray and a filter (saving money, because a Soviet electric stove for cooking scrambled eggs is lying around in every third garage, and stoves like Webasto and other systems cost a lot of money).

The method will help those who have very bad diesel fuel, which waxes and turns into a gel. Well, for example, summer. There's a problem with the water issue - if you don't start it, then until spring you'll have a piece of ice instead of an engine. A joint with a burner is a danger of arson. Collective farm options - well, perhaps the villagers can do this, but the Kulibins, it seems to me that a normal person would not do such crap.

So, we have looked at all the main methods for starting a diesel engine in the cold; their combination in itself does not contradict each other. It all depends on the situation, conditions, machine and person. As you understand, I used part of method 3 (pressed the pump) and combined it with method 4, adding a little of my own - warming up the chamber before pumping fuel with the pump and after pumping.

1) Be sure and first of all check the performance of the spark plugs, their heating time and also their cooling time, many check the resistance of the spark plugs, but IMHO on such a dubak even the tester will not turn on, as was the case for me, and anyone with vision can always determine it visually. Always use only serviceable candles that heat up quickly and cool down slowly.

3) It is highly recommended to know your compression for each pot, because if you have compression, for example, 20-23 in all pots, then you don’t have much hope of starting the car at temperatures below -20. Unless the method of increasing compression by adding oil will help.

4) check the electrical part of the cold start of the engine, because if you don’t have enough energy going to the spark plugs, you won’t start them unless you try the method of forcing the spark plugs to warm up from the battery. And a lot of things are responsible for their warming up: the cold start unit (brain), the spark plug relay, the spark plug resistance, the spark plugs themselves, and maybe I forgot something else....

5) If you hear that at least 1 pot is set without these methods, then the machine has a lot of chances for a positive result. If there are 2 pots, then in theory it will start with a little effort. 3-4 pots - it will start without problems, unless you can help it a little. If the pots don't set, increase the compression IMHO.

Well, that’s all I think for now. This concludes my article. I sincerely hope that your car will not suffer from frost and will start safely only from your love for it :-)

Organizer MMC Libero Club, Slavyan