But in addition to what we mentioned above, some old drivers also know that "three oils and three filters" play an inseparable role in the work of cars. Moreover, they can also be classified as "wearing parts" that auto mechanics often say need to be replaced in time.
In fact, there are many wearing parts in a car, and many novice drivers may be confused. What are these wearing parts? What is the reason for frequent replacement?
Let's talk about "three oils" first
Different from other "wearing parts", "three oils" are not parts because of their physical properties, but as an indispensable part of automobile work, drivers should also pay attention to the state of "three oils" and replace them in time.
The "three oils" mentioned by auto mechanics are engine oil, gearbox oil and brake oil.
First, oil. Engine oil is engine lubricating oil. As the name implies, it plays the role of lubrication and reducing wear. For an engine that runs thousands of times per minute, its importance can be seen. When engine oil circulates inside the engine, it can not only play a role of lubrication, but also bring the dirt on parts and metal debris generated by friction back to the oil pan through circulation, thus playing a role of cleaning. In addition, it also has the functions of auxiliary cooling, rust prevention and corrosion protection, shock absorption and buffering.
It can be said that the cleaning function of engine oil will soon make the new engine oil added to the engine dirty, that is, the old drivers say that the engine oil turns black. In addition, the high temperature and friction of the engine will also lead to the gradual failure of the engine oil, so when the engine oil reaches the replacement standard, it is necessary to replace the new engine oil to prevent the engine from working badly, leading to engine wear or even scrapping.
Different models have different oil change cycles, and car owners can refer to their car maintenance trolleys. Generally speaking, the replacement cycle of engine oil and engine oil for domestic cars, Japanese cars and Korean cars is 5000 km or 6 months, and the replacement cycle for new German cars is 7500/ 15000 km or 1 year.
Secondly, transmission oil. Everyone has seen gears, and the automobile gearbox is composed of many gears. Its working process is realized by the "meshing" of different gears, and wear is indispensable in this working process. In order to reduce wear and prolong the service life of gears, transmission oil is very important.
At the same time, there is also a hydraulic torque converter in the popular automatic gearbox, which works like a windmill. When air blows over the sector of the windmill, the windmill rotates with it. In the torque converter, the function of gearbox oil is the same as that of air for windmill.
When the gearbox works, the gearbox oil also plays the role of lubrication and cleaning, so it will gradually become turbid and lose its due role. Generally speaking, the oil change cycle of manual gearbox is 60,000 km, and that of automatic gearbox is1.20,000 km. Some models also use a maintenance-free automatic gearbox, and there is no need to change the gearbox oil.
Third, brake oil. The car should not only run fast, but also stop. Braking plays an important role. However, if you want a high-speed car to stop in just a few tens of meters, the braking force should not be underestimated. Generally speaking, the total braking force of ordinary compact cars is about 8000N- 10000N, but it is obviously not advisable to rely solely on manpower to obtain such a large braking force, and the brake booster pump plays such a role. With the help of hydraulic principle, it can make the vacuum when the engine works multiply the strength of the brake pedal.
During this working process, the temperature of brake oil will rise to 200 degrees or even higher, and its performance will decrease due to deterioration over time. Coupled with the debris generated by the wear of the brake pump and the absorption of moisture in the air, the braking force will be greatly weakened or even invalid, so generally speaking, the brake oil needs to be replaced when the car travels 40 thousand kilometers.
In addition, in addition to the "three oils", the high temperature generated by the engine at work needs coolant to help reduce it, which is also extremely important for the car. In the long-term high-temperature work, the composition of the coolant will change, and the alcohols in it will gradually evaporate, the boiling point will gradually decrease, and the cooling effect will become worse. At this time, a new coolant needs to be replaced.
Let's talk about "three filters" first.
"Three filters" are air/air filter, gasoline filter and oil filter. When the automobile engine is working, fresh air and clean gasoline need to be mixed in a certain proportion, otherwise a large number of pollutants will be produced during combustion, some will block the exhaust passage, and some will stick to the cylinder wall, resulting in poor engine operation. Therefore, before the air and gasoline enter the engine, they need to be filtered to ensure the cleanliness of the air and gasoline, so there are air filter elements and gasoline filter elements.
At the same time, engine oil is also needed for lubrication when the engine is running. In order to reduce the influence of impurities on lubrication, the oil pump will pump the oil in the oil pan into the oil filter element to filter impurities, and then pump it into the crankcase to provide lubrication for the engine.
The function of air conditioning filter element is very similar to that of air filter element, which can fully filter particles, flocs and other impurities in the air, so that the air sucked into the car by air conditioning system is no longer dirty.
Compared with "Three Oils", the replacement cycle of "Three Filters" is not very strict. As long as the filter element is not damaged or dirty, it can continue to be used. However, in order to keep the car in a healthy working condition, the driver can refer to the maintenance and replacement cycle provided by the manufacturer for replacement.
Third, spark plugs.
As we all know, the engine burns gasoline, converts the chemical energy stored in gasoline into high-temperature gas, and pushes the piston to do work to output power. So with gasoline and air, it needs to be ignited, so the spark plug is equally important.
As the name implies, spark plug is a part used to generate electric spark and ignite combustible gas. And the normal working temperature of spark plug is 450? Between 870℃ and 870℃, high temperature will easily lead to electrode deformation and insulator cracking. However, low temperature sea is likely to cause carbon deposition around the spark plug, which will affect its work. At this time, the spark plug needs to be replaced.
Generally speaking, the replacement cycle of ordinary nickel alloy spark plugs is 20,000-40,000 kilometers, and some high-performance models use platinum or iridium spark plugs, and the service life can reach 8-65,438+10,000 kilometers.
Fourth, timing belt.
Perhaps many novice drivers still don't know that car maintenance needs to replace the engine belt in addition to the three oils, three filters and spark plugs. Generally speaking, there are three belts on an engine: timing belt, water pump/generator belt and air conditioning belt, and there is also a booster pump belt on a car that uses hydraulic power steering. Among them, the timing belt is the most important for the engine, which can drive spark plugs, intake and exhaust valves, fuel injectors and so on. Intervene at a reasonable time. If the timing belt is broken, the engine will not work and even cause engine damage.
Damage to the timing belt may cause engine damage.
Generally speaking, the replacement cycle of the timing belt is 60,000 kilometers. Nowadays, many cars use timing chains instead of timing belts, which have obvious advantages: durability and no need for maintenance. But the disadvantage is also obvious: the noise is too high when the engine is running.
Brake pads/discs.
As mentioned above, the car can stop safely by the powerful braking force provided by the brake booster system, while the process of slowing down the car depends on friction. When the brake pad and the brake disc are tightly engaged to produce friction, the kinetic energy of the automobile is converted into work when the braking system overcomes the friction and the generated heat energy.
Therefore, in general, the brake pads will be replaced when a car travels 40,000 kilometers, but some novice drivers don't know that in addition to the brake pads, the brake discs will gradually wear out and need to be replaced. The replacement cycle is generally 8-65,438 438+ 10/00,000 kilometers.
Sixth, tires.
Similar to the work of brake pads and brake discs, the reason why a car can run forward depends on the tire rolling to overcome the friction of the road surface, so the tire surface will gradually wear. Over time, the friction of tires will be reduced, and the effect of "grasping the ground" will be greatly reduced.
In addition, tires exposed to the outside of the car for a long time will age and crack under wind and rain, and their performance will be greatly reduced. Therefore, when the tire crown is worn below the scale line, or the tire rubber cracks and leaks, it needs to be replaced with a new one.
Seven, the battery.
You may find it incredible to classify batteries as "wearing parts". At present, almost all batteries used in automobiles are lead-acid batteries. When discharging, metal lead is the negative electrode and is oxidized into lead sulfate. Lead dioxide is the positive electrode, which is reduced to lead sulfate by reduction reaction. When charging, the opposite chemical reaction occurs, and lead and lead dioxide are generated at the two poles respectively.
It seems that this reversible chemical reaction of the battery enables it to be used indefinitely, but this is not the case. In the process of battery charging, not all lead sulfate can be converted into lead oxide, but they will form crystals attached to the electrode, which will reduce the contact area between the electrode and electrolyte and the concentration of electrolyte, thus reducing the performance of the battery.
In particular, long-term overdischarge will accelerate this irreversible chemical reaction, and the uneven distribution of active substances on the battery plate will also lead to the battery falling off due to different expansion tension during discharge, which will promote the battery failure. Just like electronic devices such as mobile phones and charging treasures that are used every day, the endurance becomes worse after a long time. The most direct reaction is that you can't charge the electricity, especially in winter, and you can't start the car after one night.
Eight, wiper.
Many drivers have this experience. When driving out in the rain, I turned on the wiper and found that the wiping effect became worse, even the clean water was scraped away. It's time to replace the wiper. The reason for this is that when the wiper works, it always rubs against the windshield. Over time, the rubber strip on the wiper is no longer smooth, and the wind and rain further accelerate its aging, which eventually leads to the inability to scrape off the rain on the windshield.
Nine, light bulbs.
Why do light bulbs also have wearing parts? Take the most common halogen bulb as an example. It emits light by energizing the filament, which is heated to incandescent state. When the filament heats up, a part of the filament will vaporize and slowly deposit on the bulb wall, and the filament will gradually become thinner and eventually break. Generally speaking, the service life of halogen bulbs is about 500 hours. If the car always runs at night, it will be scrapped even without a maintenance cycle. The life of xenon headlights is longer, about 3000 hours, and the theoretical life of LED headlights can reach 654.38+ 10,000 hours.
Speaking of which, do you think it is not easy to keep a car?