The cold season is always a test, both for the car and for its owner. Morning car rituals in winter turn into real “dances with a tambourine” - start, warm up, defrost, clean ... And if earlier the question of the need to warm up the engine before driving was not in doubt, today we increasingly hear that modern engines need to warm up not needed. So to heat or not to heat? Let's figure it out.
What is heated and how?
How to determine if the engine is warm or not? It is generally accepted that it will be fully warmed up when, under a fixed operating mode, the temperature indicators of all its parts and liquids stop changing. Many people estimate the engine warm-up level from the corresponding indicator on the dashboard, although in fact it reflects the temperature of the coolant, which heats up the fastest. Together with it, the upper part of the engine - cylinders, head, pistons - warms up quickly enough. The sump warms up much more slowly along with the oil in it - even when the coolant temperature gauge needle reaches the “working” level, the oil in the sump may still remain unheated. The last to warm up is the exhaust gas toxicity converter.
Assessing risks
A modern engine is a complex structure that includes parts made of different materials. Often one of the mating parts can be made of aluminum, and the other can be made of cast iron or steel. These materials have different coefficients of thermal expansion. Simply put, under different temperature conditions, parts made of these materials will have different sizes.
For example, the gap between the piston and the inner surface of the cast-iron cylinder block at low temperatures is quite large, and when the engine warms up, it gradually decreases due to the thermal expansion of metals. At an air temperature of +20 degrees Celsius, the nominal clearance of the piston in the cylinder is approximately 0.04-0.06 mm. In frost -30, the gap increases to almost 0.1 mm, and with such gaps the piston inevitably knocks on the surface of the cylinder, causing accelerated wear of parts. While the engine is idling, the knocking is not so strong, but if you give a cold engine a load, scuffing can occur on the piston skirt, on the piston rings and on the cylinder itself. These damages will inevitably lead to a drop in compression and an increase in oil consumption. In addition, increased clearance causes working gases to enter the crankcase, which can lead to accelerated oil oxidation and loss of power.
Another “piston” problem is the temperature difference on the surface of the piston and cylinder. If you start moving immediately after starting the engine, and even give the engine a load - for example, stall in a snowdrift at the exit from the yard - you get a very dangerous situation. The bottom of the piston will be quickly heated by heat flows from the working fluid, while the cylinder walls will still remain cold. Grooves for piston rings are cut on the side surface of the piston, and these grooves are very sensitive to extreme loads - namely, they will experience such loads with the temperature difference described by us.
The piston is not the only source of potential problems that can be encountered. Any car owner knows that one of the main dangers of a cold start is insufficient lubrication. That is why in the cold season you can not do without high-quality engine oil with the appropriate viscosity. The lubrication system of all modern engines, which, as you know, are compact in size, has very thin channels, which are especially sensitive to oil viscosity. In addition, low-quality oils at low temperatures can form deposits on internal surfaces and engine parts during operation, which will inevitably lead to problems.
Another important point is the increased fuel consumption characteristic of a cold engine. At low temperatures, the electronics increase the supply of gasoline, and until the engine reaches operating temperature, fuel consumption during movement will be quite high - much higher than in a warm engine.
It turns out to warm?
So, it turns out that warming up the engine before starting to move is simply necessary. However, this medal has another side.
While the engine is cold, the electronics supply a rich air-fuel mixture inside. The fact is that in severe frost, the fuel does not evaporate well enough, plus cold winter air enters the cylinders. To cope with these shortcomings of a cold engine, the electronics begin to pour significantly more gasoline into the engine, which dramatically increases the level of CO and CH emissions. It is not for nothing that “morning” exhaust gases are considered the most caustic - their smell penetrates literally everywhere. In addition, when idling, the engine warms up much more slowly than when driving, respectively, the level of emissions also increases.
Modern electronic injection systems reduce the problem by precisely metering fuel, which not only reduces emissions somewhat, but also improves cold engine performance. However, this is not enough to reduce the level of environmental damage - the percentage of obsolete cars on Russian roads is still quite high. Another solution to the problem of exhaust gases is an emission control system equipped with a catalytic converter. Such systems are now installed on almost all modern cars. However, the work of the converter is effective only when it is warmed up to operating temperature. In some cars, forced electrical heating of the converter is installed, but there are still very few such instances. This means that until the car warms up properly, the converter will not cope with its task. Moreover, if you warm up the engine in the parking lot at idle, the converter will heat up much more slowly, and will only return to its operating mode when you start moving.
There is a long warm-up and another drawback. At low temperatures, water vapor can form on the surface of the cylinder. During a cold start, it comes into contact with nitrogen oxides, which are formed in the internal combustion chamber during engine operation, especially diesel. The result of the combination of water vapor with nitrogen oxides is weak nitric and sulfuric acids, which can lead to thermochemical corrosion of the internal surfaces of cylinders and engine parts. The longer you warm up the engine, the more intense the corrosion processes will be.
What is the result?
So, it is still necessary to warm up the engine before driving - this allows you to reduce the wear rate of parts, delay major repairs and save money. At the same time, prolonged warming up causes significant environmental damage, increases fuel consumption, and is also unsafe for the engine itself. That is, it is also wrong to warm the engine for a long time.
So where to look for the notorious "golden mean"?
For an answer to this question, we turned to the experts of "Auto and City" - specialists in the field of car maintenance.
Artem Filatov, director of the service station "Master-service":
“In my personal opinion, it is still necessary to warm up the engine, depending on the model of the car - until the arrow reaches operating temperature, or until the corresponding light goes out, indicating that the engine is cold.
In itself, the movement of a cold engine is not scary, large loads are terrible. Until the engine is warmed up, all its rubbing pairs, due to the high coefficient of expansion of the metal, have ineffective gaps between themselves, and wear increases accordingly. If you avoid excessive loads (revs above 2000-2500, sudden accelerations, etc.), you can move - modern cars are quite capable of this. However, in our conditions it is almost impossible to move without a load - the roads are not cleaned, you skid, you have to step on the gas. In addition, at -30 in the car, not only the engine freezes, but also the transmission, chassis, it’s just hard for it to move off - and this is again an additional load.
There is another important point - many modern cars do not tolerate "idle" warm-up. That is, if you have already started and warmed up the car, it should go. Initially, any car was designed for this - and in Europe this is exactly what they do because of environmental prohibitions. If the car constantly starts at auto start, warms up and then turns off without further movement, this is no less dangerous for the engine, like driving without warming up, and maybe even worse. Under this mode of use, condensate accumulates in the engine, and this can lead to engine oil failure, accelerated aging, and loss of oil properties. There was one case, quite well-known in our circles, when a girl bought a new car at a car dealership, but she did not yet have a driver's license. While she was solving the issue with the rights, her father regularly warmed up the car for several months without moving, believing that in this way he would "run in" it well enough. As a result, the engine failed with a run of less than a hundred kilometers. This case was recognized as non-warranty, as the operating conditions were violated - moisture accumulated in it, and a completely new engine was damaged. If in the near future you do not need to drive, then it is better to remove the car from autorun and do not touch it at all, do not start it. Ideally, remove the battery and take it home. The main thing is that during the subsequent plant there should not be an extremely low temperature on the street.”
Rinat Khamitov,
director
car center
Pleiades:
“In the winter season in our climate, it is necessary to warm up the engine. The average warm-up time for almost all cars is 7-10 minutes, which is exactly how long it takes for the coolant temperature to rise to its minimum operating level - up to 40 degrees. There is a slight difference between car brands - European cars, like most "Americans", do not have a car warmed up from the factory, as Europe is actively fighting for environmental friendliness, and Europeans are ardent opponents of the car standing at idle and warmed up. That is why in European cars, unlike Japanese ones, there are no so-called “warm-up revolutions”. Japanese cars warm up at 1500-1700 rpm, "European" in 5-10 seconds after the plant goes to 800-1000 rpm. Despite this, in our climate they definitely need to be heated until the oil reaches its operating range, because it has different lubricating properties for cold and hot, forming a different oil film, and the engine is quite heavily loaded during cold start. It is believed that one cold start is conditionally equal to approximately 30-40 kilometers. In addition, the warm-up time largely depends on the design of the engine itself. Take, for example, the Japanese brand "Subaru" with which we work. The engines of these cars are very categorical both to a cold start and to movement without warming up. They like a long warm-up - up to 15-20 minutes. The fact is that Subaru's boxer engine has its drawbacks - it stands horizontally, and until all nodes acquire the working clearances necessary for the proper operation of the internal combustion engine, it will take more time. In addition, you need to warm up the engine, regardless of whether it is diesel or gasoline. Moreover, it is more difficult to warm up a diesel engine; it is not for nothing that many diesel cars already have an installed pre-heater installed from the factory, which makes starting easier. It is also very important to warm up the chassis and transmission, but this warming up takes place already while the car is moving, during slow driving. Of course, when the engine warms up, the transmission also heats up, but not much, and the main heating of the gearbox occurs on the go. Hodovka heats up only while driving, and in order not to squeeze out the oil seals of the struts, not to pull out the silent blocks, and so on, you need to move carefully - at least 2-5 kilometers drive very carefully.
In this article, we will try to explain to you why it is worth warming up the engine before a trip. We will tell you all the pros and cons of warming up. Let's touch on the topic of autorun. The peculiarity of our country is the large difference in air temperatures. During the year it varies from +30 to -30 degrees. These conditions dictate to us such requirements as high-quality oil and warming up the engine before the trip.
What happens to the engine during a cold start? The oil in the engine becomes very thick during the night stay. The longer the car is on the street and the lower the air temperature, the worse it is. You probably noticed that in the morning, with a cold start, the engine is reluctant to spin with a starter, although after a working day the car starts up quite easily. The answer to this question is simple. At night, the air temperature drops by at least 3-5 degrees more, and the car stays longer at night than during the day and, accordingly, freezes more. In addition to the oil in the engine, oils in the gearbox and in the gearbox acquire the consistency of semolina. You say that you have an automatic? The machine also has gear oil! Automatic Subaru two section. The first section - the front gearbox in which gear oil is filled, the second section - clutches, valves, etc. - ATP is filled there. Which also thickens in the cold, although not as much as the transmission. Gearboxes also have gear oil. What does all this say? This suggests that the car simply freezes. Cold, frozen oil does not work fully, its lubricating properties decrease at low temperatures. Therefore, a cold start for the engine is already stressful in itself, but if you also immediately set off on the road, then you may not reach your destination at all.
So how should you warm up your car? It is the car, below you will understand why. Before starting, get in the car and depress the clutch pedal. This is necessary in order to facilitate the work of the starter, when the clutch is depressed, the engine will not scroll through the gearbox. With the pedal released, in addition to the engine, the starter will also have to rotate the shafts in the box, and the oil is thick there, which will lead to significant friction losses, and the engine will scroll sluggishly, and it’s not at all a fact that it will start. Moreover, at very low temperatures, the possibility of rolling the car forward is not ruled out, although the box is in neutral gear. How does this happen? The oil in the box is very thick, the gears practically stick to the shafts, due to this, a "Engaged gear" is obtained. Of course, the car will not go far, but there were cases that the car drove half a meter, and sometimes this is enough to ruin your day, and your neighbor to boot. The automatic transmission should be left in the parking lot. The machine doesn't interfere much with starting. I also advise you to turn off all electrical appliances, such as music (especially with amplifiers), headlights and dimensions. You don't need to do any more manipulations. Turn the key, wait for the fuel pump to work and start.
The engine started. Probably everyone noticed that a cold engine runs louder and noisier than a warm one. This is due to the fact that all engine parts are cold, the gaps are large. The pistons rattle their skirts against the cylinder walls. In the process of warming up the engine, all its parts heat up, and, accordingly, expand, the gaps return to normal, with warming up, the sound of the engine becomes quieter. Now the temperature arrow has settled down in its favorite place, and it seems that you can already go ... But do not rush. At this point, the oil in the engine has not yet reached 50 degrees. Better to wait another five minutes. And that's just the engine.
Now let's discuss the rest of the car's systems. The automatic machine warms up together with the engine, the automatic fluid circulates through the engine cooling radiator and thus also warms up. Therefore, these 5-10 minutes that you wait after setting the operating temperature are very important for minimal warming up of the automatic fluid. Some models with mechanical gearboxes also have such cooling and heating. Our gearboxes are not heated in any way, as well as the fluid in the power steering. Therefore, before you go, turn the steering wheel gently, but not all the way. Depress the brake pedal. The power steering fluid will warm up while driving. For the first three to five kilometers, try to move without sudden accelerations and braking. Carefully drive through the pits and speed bumps, because. there is oil in the shock absorbers too! It is also thick, and you probably noticed that a cold car jumps on bumps for the first kilometers of the distance. This is due to the fact that there is thick oil in the shock absorbers, the principle of operation of the simplest shock absorber is the flow of oil through the valve. Imagine a simple medical syringe with a hole in the plunger and a sealed spout. Mentally pour a little oil into it and insert the piston, push. Oil will flow through the hole to the top of the piston, the piston will move slowly and smoothly. This is how a shock absorber works. Thick oil flows much worse through the hole, and in the shock absorber. On large pits, the load on the shock absorber increases, which can lead to breakage with cold oil. And it is worth mentioning that cold shock absorbers do not work adequately and the behavior of your car can surprise you unpleasantly.
Autorun is just a bonus. In everything. There are a couple of disadvantages, for example that there is no way to squeeze the clutch. Or if the car does not start, the signaling may try to start it until it turns blue and land the battery. And during autorun, do not direct the air flow to the glass if your stove is active, because. a sharp stream of hot air to the windshield can cause it to crack. The rest of the minuses are not visible.
Summarize. The engine needs to warm up! And not only him, you need to warm everything. It is not for nothing that athletes in severe frost try to get to the next special. area as close as possible to his starting minute. Everything freezes when the car is stopped. If you are really on fire, and you need to urgently go, and there is no time to warm up the car - first gear, no higher than 2000 rpm until everything warms up.
Getting ready in a timely manner
The first condition for trouble-free winter operation of the car is advance preparation. Even before the onset of cold weather, experienced drivers changed the spark plugs, replaced the engine oil with winter oil and replaced the filters, checked the drive belts and the battery. If the fuel is of high quality, and the car is in good condition, with a fresh battery, normal spark plugs and a starter, starting at temperatures down to -35 ° C is not a problem. But those who hoped for a chance will inevitably expect surprises with the engine starting even in a not so severe frost.
Getting Started
Here it is - the moment of truth. The thermometer is about -20 ° C, and the car stood all night in the open. Well, if you immediately "grabbed". And if not? Turn on high beam before trying to start. But not for half a minute, as many advise, but literally for 8-10 seconds. This is enough to warm up the battery a little, and there is no risk of planting it. Next, you need to squeeze the clutch and put the gearshift lever in neutral (on a car with an “automatic” it is recommended to move the selector from position P to position N) and turn on the ignition. As soon as the fuel pump runs (it takes a few seconds), you can turn on the starter - but no more than 15 seconds.
An unsuccessful attempt can be repeated after one or two minutes. This pause is needed not only in order for the battery to regain strength: the gasoline that has flooded the candle wells must be allowed to evaporate. The main thing is not to get carried away. If the car did not start the third time, then it is unlikely to start today at all. Putting the battery and raping the engine further does not make sense.
If the engine comes to life, do not rush to release the clutch. This should be done smoothly, observing the speed and only when the engine runs smoothly. By the way, it is dangerous to “help” a sneezing engine with gas supply: the risk of flooding candles is too great, and the cylinder purge mode will not work in severe frost.
For those who are not afraid of auto chemicals, we recommend aerosol "start-up aids" in the form of a cylinder with a nozzle tube. An ethereal spray is injected into the air intake (you'll have to look for it under the hood) and facilitates the ignition of the mixture. Suitable for both petrol and diesel engines. However, experts advise not to get involved in this.
To warm or not to warm?
It is believed that a modern motor does not need to be heated. This is true, but only for minor sub-zero temperatures. In severe frosts, the oil thickens too much, it is advisable to let it “disperse” and at least slightly lubricate the rubbing parts.
Experts advise warming up for 3-5 minutes, for cars with automatic transmission - 5-10. In the latter case, it is useful, while holding the brake pedal depressed, to drive the selector from position P to N, D, R and back, lingering in each position for several seconds.
To speed up the warm-up of the motor, you can turn off the stove. In severe frost, it is best to wait until the antifreeze temperature arrow “comes to life”, and warm air comes out of the nozzles. Even if there is no warm-up time at all, it is recommended to stand still for at least a couple of minutes - until the speed drops to idle, and move at a calm pace for the first few kilometers, without increasing speed.
It is equally important to go around all the pits and other irregularities: until the hardened shock absorbers have warmed up, there is a high probability of their breakdown and costly replacement.
With the onset of winter, disputes about the correct operation of the car at low temperatures are activated. Some drivers try to properly warm up the car at idle. Others believe that this is an unnecessary procedure. Which of them is right?
The temperature range in autumn and winter in central Russia is within 30 degrees. Sometimes the weather changes abruptly and what cannot be done at zero degrees turns out to be necessary in the cold. Consider first the arguments against warming up the motor.
Pollutes the atmosphere with harmful gases
Indeed, idling is considered the most toxic. The operation of the motor without load is the cause of the synthesis of nitrogen oxides and other toxic emissions. It is in order to comply with Euro 5 standards that automakers cut off idling modes using the Start-Stop system, which turns off the engine during stops. Naturally, these same standards prescribe to warm up the car not at idle, but while driving.
Prevents residents from sleeping
A running engine not only smells bad, but also creates unpleasant acoustic waves. He, roughly speaking, rumbles, especially on old worn-out equipment. And this causes dissatisfaction with people under whose windows a car is started in the morning. The most unpleasant thing is that during a cold start, low-frequency waves go through the exhaust system, thanks to which windows even ring in the surrounding houses.
Prohibited by law and subject to fines
Warming up the car in residential yards is prohibited by law. If someone sees and fixes this process on video, then the owner can be fined. Recently, hunting for motorists is common among pensioners and teenagers. There are programs for mobile smartphones with which you can shoot and send video to law enforcement. Then it’s a matter of technique, and the fine is 1,500 rubles under Article 12.28 of the Code of Administrative Offenses of the Russian Federation (“Violation of the rules established for the movement of vehicles in residential areas”). The same violation in Moscow or St. Petersburg is already estimated at 3,000 rubles.
Increased fuel consumption
Security electronic systems with remote start help to start the car without leaving the apartment. You can press a button, and the motor will start to rumble in the cold, dousing the body with white fumes. Sometimes it takes 20-25 minutes until the owner appears in front of the car. Naturally, this procedure entails increased fuel consumption. On average, at idle, a 2.0-liter 4-cylinder cold engine spends 1-1.2 liters of gasoline per hour.
All of the above arguments are valid for warm weather and off-season, when the air temperature does not fall below 5 degrees below zero. But what if the frost hit? In this case, there are four irrefutable arguments for warming up the motor.
Solidified oil does not have time to pump
Any oil, even synthetic, has an operating temperature range in which its declared characteristics are maintained. If cold weather sets in and frosts hit below 20 degrees, then 5W30 oil loses viscosity. It is designed to work from -25 to +25 degrees. At borderline temperatures, the oil thickens. Therefore, before driving, the oil temperature must be raised to operating temperatures.
The pump must pump oil through the lubrication system
Modern engines and automatic transmissions have oil pumps to help circulate the lubricant. The oil also works in the torque converter. Therefore, the oil must not only warm up, but also pump through complex channels, which takes time. The less stress the motor and gearbox experience during a cold start in a frosty winter, the better.
The box warms up last
Heat reaches the gearbox last. If the motor has a small volume, then it will take about 10 minutes until the most important units stop experiencing oil starvation and restore the performance declared by the manufacturer. Therefore, in cold weather, it is imperative to let the car work longer at idle.
Uneven thermal expansion
Another enemy of the car is uneven thermal expansion. With a sharp heating under heavy load, parts made of different materials begin to increase in size in different ways. With viscous oil, rubbing surfaces experience a lack of lubrication, the oil film breaks through, and metal wear begins. If, immediately after a cold start, you start driving fast with frequent spinning of the engine up to 4-5 thousand revolutions, then there is a high chance of damaging the inner surfaces of the cylinders. Bumps will appear. In general, the engine cannot drive as well in cold weather as it does at zero degrees. It must be warmed up to bring the temperature of the coolant and oil to at least zero degrees.
