Engine oil, namely engine lubricating oil, English name: Engine oil.The density is about 0.91 × 10 ³ (kg/m ³)engineIt plays the role of lubrication and antifriction, auxiliary cooling and cooling, sealing and leakage prevention, rust prevention and corrosion prevention, shock absorption and buffer, etc.It is known as the "blood" of automobiles.Oil fromBase oilAnd additives.Base oil is the main component of lubricating oil and determines the basic properties of lubricating oil. Additives can make up for and improve the performance of base oil and give some new propertiesLubricating oilAn important part of.
The engine is the heart of the car. There are many metal surfaces that rub against each other in the engine. These parts move fast and in a poor environment. The operating temperature can reach 400 ℃ to 600 ℃.The new technology can make natural gas into crystal pure synthetic base oil. On this basis, unique power cleaning technology can be added to create lubricating oil with super cleaning and protection performance.Under such severe working conditions, only qualified lubricating oil can reduce the wear of engine parts and extend the service life.The engine oil on the market can be simply divided into mineral oil and synthetic oil due to their different base oils (vegetable oil is not counted because of its scarce output).Synthetic oil is divided into full synthetic oil and semi synthetic oil.Lubricating oil base oilIt is mainly divided into two categories: mineral base oil and synthetic base oil.Mineral base oil is widely used, with a large amount (more than 95%), but some applications must use products blended with synthetic base oil.
requirement
As a kind of machinery, the engine has a common requirement for lubricating oil compared with general machinery, such as proper viscosity, certain performance requirements for oxygen resistance, abrasion resistance, corrosion prevention and viscosity temperature.However, the engine is a special kind of machinery, and its requirements for lubricating oil have its own special aspects, which mainly include:
1) The general requirements for the engine are small size, light weight, compact mechanism, and large output power, so the load on the unit friction surface is very large.
2) In addition to the friction heat, it is also affected by the combustion heat, so the temperature of the friction surface is very high, which reduces the viscosity of the lubricating oil and makes it difficult to form an oil film.
3) The high-temperature and high-pressure combustion gas in the combustion chamber will leak to the crankcase through the gap between the piston, piston ring and cylinder liner. These combustion gases are the gas and some particles (soot) produced by the complete combustion and incomplete combustion of fuel and a small amount of lubricating oil, usuallyCrankcase blow byIt will pollute the lubricating oil and, under certain conditions, promote its oxidation.
4) The lubricating oil needed around the combustion chamber is through the clearance between the piston and cylinder liner, valve stem andValve guideIt is difficult to supply oil because of the gap between.
5）pistonandvalveWhen working, the parts, etc., make reciprocating motion, so the relative speed at the top and bottom dead center is zero, which makes it difficult to form oil film.The piston pin and bushing are in swing motion, and the oil film is difficult to form.
6) When the engine is stopped and operated for a long time, the temperature difference is very large, and because of the thermal expansion and thermal deformation of parts, it is difficult to control the constant clearance of some friction pairs, which may lead to adhesive sintering due to too small clearance, or damage due to impact and vibration due to too large clearance.In these cases, the oil film is difficult to adhere.
7) There are many kinds of friction pairs in the engine, such as piston and cylinder liner, crankshaft journal and bearing, cam and follower, gear, etc. Although they have different requirements for lubricating oil, only one kind of lubricating oil (largemarine dieselTherefore, various lubrication conditions shall be taken into consideration when selecting lubricating oil.
8) The operating environment of vehicle engines is complex, such as temperature, humidity, atmospheric pressure, dust, etc.At the same time, the engine oil often contains sulfur, lead and other elements, which will promote the corrosion and wear of certain parts.
Level division
By viscosity
10W-40 is its SAE standard viscosity value. This viscosity value first indicates that the engine oil is multi-stage engine oil. W represents Winter. The number in front of W represents the flow performance at low temperature. The smaller the value, the better the starting performance at low temperature.The number after W represents the stability of engine oil at high temperature (i.e. the possibility of thinning). The higher the value, the better the stability of engine oil at high temperature.
Four stroke oil:
The viscosity grade classification of four stroke oil is applicable to the classification of Society of Automotive Engineers and SAE classification
SAEViscosity of lubricating oilThe classified winter oil grades are: 0W, 5W, 10W, 15W, 20W, 25W. The symbol W represents winter. The smaller the number before W, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the applicable minimum temperature;
The summer oil grades of SAE lubricating oil viscosity classification are: 20, 30, 40, 50. The higher the number, the higher the viscosity, and the higher the applicable maximum temperature;
The winter and summer general oil grades of SAE lubricating oil viscosity classification are: 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, 10W-50, 15W-20, 15W-30, 15W-40, 15W-50, 20W-20, 20W-30, 20W-40, 20W-50. The smaller the number representing the winter part (the lower the applicable minimum temperature), the larger the number representing the summer part (the higher the applicable maximum temperature),The wider the applicable temperature range.
Two stroke oil:
The viscosity grade classification of two-stroke engine oil is applicable to the classification of Society of Automotive Engineers and SAE classification
Two stroke gasoline engine oil has two viscosity grades, namely, SAE20 and SAE30. Generally, SAE30 is selected. If it is separately lubricated, it can be used in cold areas or ultra light loadTwo-stroke engineThen use SAE20
Selection of viscosity grade:
SAE viscosity code:
100℃ m㎡/s
SAE
min
max
twenty
thirty
forty
fifty
sixty
five point six
nine point three
twelve point five
sixteen point three
twenty-one point nine
nine point three
twelve point five
sixteen point three
twenty-one point nine
twenty-six point one
Reliable point of cold start:
The reliable point of cold start is+5 ° of the critical pumping temperature.
In this temperature range, the car has good technical conditions, and there is no problem during the cold start process.
SAE 0W
-40℃
+5℃
-35℃
SAE 5W
-35℃
+5℃
-30℃
SAE1 0W
-30℃
+5℃
-25℃
SAE 15W
-25℃
+5℃
-20℃
SAE 20W
-20℃
+5℃
-15℃
SAE 25W
-15℃
+5℃
-10℃
Usually, we calculate the low-temperature startup. To be simple, add "- 35 °" to the number in front of W.
For example, "0W" means that it can be started normally at a minimum of minus 35 degrees,
Classification of fuel economy
Since Europe is significantly different from the United States in terms of engine design, vehicle driving conditions and government policies on energy conservation and environmental protection, this difference is also reflected in the focus and degree of attention of European automobile manufacturers on engine oil performance.The European automotive industry attaches great importance to energy conservation, putting automotive fuel economy in the first place, and giving consideration to both power and emission performance.
The latest 2007 edition of the ACEA European Classification Standard for Lubricating Oils is classified into three families.They are:
A/B series: gasoline and light load diesel engine oil
Class C: suitable for catalyst engine oil
E series: heavy duty diesel engine oil
The A/B series includes: A1/B1;A3/B3；A3/B4；A5/B5。
Series C includes: C1;C2；C3；C4。
E series includes: E2;E4；E6；E7。
Quality grade selection
The quality grade of engine lubricating oil, also known as service performance grade, is an important basis for correct selection of lubricating oil.
1. Diesel engine oil
There are two main bases for the selection of diesel engine lubricating oil quality grade.First, based onautomobile engineThe sum of mechanical load and thermal load of, expressed as strengthening coefficient;Then, according to the severity of engine operating conditions.
For high-speed naturally aspirated andTurboFour strokeDiesel engineDiesel engine oil above CF-4 shall be used.For high-speed four stroke diesel engines that appeared after 1998, in order to meet the requirements of engine technology improvement and emission regulations, diesel engine oil above CH-4 level should be used. CH-4 level can replace CF-4 and CD.High speed four stroke naturally aspirated, turbocharged and heavy-duty diesel engines produced after 2002 should use diesel engine oil above CI-4, which can replace CH-4, CF-4 and CD, because of the existence of exhaust gas recirculation devices, the requirements of formula regulations and the requirements of exhaust gas aftertreatment technology.
2. Gasoline engine oil
The gasoline engine oil with the corresponding performance level (quality level) shall be selected according to the severity of the engine working conditions, the additional devices in the inlet and exhaust systems of imported vehicles and the production years.Generally speaking, high quality grade oil can replace low quality grade oil, but low quality grade oil must not be used to replace high quality grade oil, otherwise it will lead to engine failure or even damage.
If many new cars are used under normal driving conditionsSynthetic oilBasically, the engine oil can be changed every 10000 km, and some can even be towed for 20000 km.Automobile maintenance professionals believe that "normal driving" refers to driving frequently on the expressway, and rarely stopping and walking.However, if you often drive in the city, there are traffic lights everywhere, and there are always traffic jams, and the distance of each trip is not more than ten kilometers, this kind of driving is "consumable driving".
Oil change of diesel generator set
Diesel generatorAfter the group has been used for a period of time, it is necessary to change the oil. When can we change the oilDiesel generator setHow about changing the engine oil?For some friends who are not familiar with the use of diesel generator sets, it is sometimes difficult to identify.
First of all, we need to understand theDiesel generatorThe engine oil used by Group A is different. Generally, the new engine works 50 hours after the first time and 50 hours after the intermediate repair or overhaul.The oil change interval is generally the same asOil filter(filter element) at the same time. Generally, the oil change cycle is 250 hours or one month.With Class 2 engine oil, the engine oil can be replaced after 400 hours of operation, but the engine oil filter (filter element) must be replaced.
If you want to determine the replacement time of the diesel generator set accurately, you need to know some of the determination methods:
1. Use two glass test tubes with a diameter of 0.5 cm and a length of 20 cm to load 19 cm of new engine oil and used engine oil respectively. After sealing, the two tubes are inverted at the same time. Record the rising time of bubbles. If the difference between the two tubes exceeds 20%, it means that the viscosity of used engine oil has dropped too much and should be replaced.
2. Compare the new engine oil and the used engine oil on the white filter paper one drop each. If there are many black spots in the used engine oil, it indicates that the engine oil is not deteriorated and should not be replaced;If the oil is dark brown, it is deteriorated and should be replaced.
aboutDiesel generatorThe replacement of unit oil can well guarantee the stable use of the generator set, which also effectively extends the service life of the diesel generator set to a certain extent. Therefore, the replacement time of the diesel generator set must be determined accurately during the use of the diesel generator set.
A good choice of oil can make the car more durable and powerful.Good engine oil, especially fully synthetic engine oil, can not only protect the engine and reduce the number of oil changes, but also save gasoline costs.Therefore, its price is twice that of ordinary oil, which is the best choice for many car owners.
Special automobile oil may not be suitable for your car.Adding oil to the car also depends on the driving age, engine condition and regional conditions of the car. Of course, only a few specifications of special oil can not meet the requirements of a variety of vehicle conditions and regional conditions.
Park the vehicle on a level surface, turn off the engine and wait for about 5 minutes. Wipe the oil dipstick clean, insert it into the oil dipstick guide hole, and then pull it out for inspection.
The oil level is between the upper and lower scribed lines.If it exceeds the upper marking, drain the excess oil. If it is lower than the lower marking, add oil from the oil port. After 5 minutes, check the oil level again.
When replenishing the engine oil, pay close attention to the cleaning and check whether there is leakage. When checking the oil level, pay attention to the pollution degree of the engine oil.
Main role
The engine is the heart of the car. There are many metal surfaces that rub against each other in the engine. These parts move fast and in a poor environment. The operating temperature can reach 400 ℃ to 600 ℃.Under such severe working conditions, only qualified lubricating oil can reduce the wear of engine parts and prolong the service life. What requirements should qualified lubricating oil meet?That is to say, what are the seven functions of lubricating oil?
1、lubrication: Rapid relative sliding exists between the piston and cylinder, and between the main shaft and the bearing bush. To prevent the parts from wearing too fast, it is necessary to establish an oil film between the two sliding surfaces.The oil film with sufficient thickness will separate the surfaces of relatively sliding parts, so as to reduce wear.
2. Auxiliary cooling: the oil has low specific heat value and is inside the engine, so it does not have cooling effect.However, due to the heat energy generated by fuel combustion in the engine, when the engine is working, the oil can return the heat to the oil tank and distribute it to the air to help the water tank cool the engine. The real cooling effect is the water (or antifreeze liquid) outside the engine housing.
3. Cleaning: good oil can recycle the carbides, sludge and wear metal particles on the engine parts back to the oil tank, and flush the dirt on the working surface of the parts through the flow of lubricating oil.
4. Sealing and leak proof: engine oil can form a sealing ring between the piston ring and the piston, reducing gas leakage and preventing external pollutants from entering.
5. Rust and corrosion prevention: lubricating oil can absorb on the surface of parts to prevent water, air, acid substances and harmful gases from contacting with parts.
6. Shock absorption and buffering: when the pressure of the engine cylinder port rises sharply, the piston, piston chipsconnecting rodandcrankshaftThe load on the bearing is very large. This load is transmitted and lubricated by the bearing, so that the impact load it bears can play a buffer role.
7. Anti wear: adding lubricant to the friction surface can reduce the friction coefficient, thereby reducing the friction resistance, saving energy consumption and reducing wear. Lubricant between friction surfaces can reduce the friction caused by abrasive wear, surface fatigue, adhesive wear, etc
How are automobile oil grades classified?When selecting oil, the correct oil level is the first factor to consider.How to choose the one that is suitable for your car from many oil products?First of all, we should understand the classification method of automobile oil grade.
Lubricant additives
Additives are the essence of modern advanced lubricating oils. Proper selection and reasonable addition can improve their physical and chemical properties, endow lubricating oils with new special properties, or enhance their original properties to meet higher requirements.According to the required quality and performance of lubricating oil, the key to ensure the quality of lubricating oil is to carefully select, carefully balance and reasonably allocate additives.
Under various conditions, the ability of engine oil to reduce friction, slow down wear and prevent metal sintering is called engine lubricity.
The viscosity of engine oil is an important index for evaluating lubricity.
Low temperature operability
The low temperature operability of engine oil is to ensure that the engine can be easily started and reliably supplied at low temperature.
The low temperature operability of engine lubricating oil includes two aspects: being conducive to low temperature starting and reducing starting wear.
Low temperature dynamic viscosity, boundary pumping temperature and pour point are the main indexes to evaluate the low-temperature operability of engine lubricating oil.
Viscosity temperature property
The viscosity of lubricating oil changes due to temperature rise and fall, which is called viscosity temperature property.
Good viscosity temperature property means that the viscosity of oil changes little with temperature.
The influence of temperature on oil viscosity: the viscosity decreases with the increase of temperature;When the temperature decreases, the viscosity increases.
Adding viscosity index improver to base oil can improve the viscosity temperature property of oil products.
The engine oil, which is formulated with low viscosity base oil and viscosity index improver, has good viscosity temperature property and can meet the requirements of low and high temperature use at the same time, is called thickened oil or commonly referred to as multi-stage oil.
The index for evaluating the viscosity temperature property of engine oil is the viscosity index.
The ability of engine oil to inhibit the formation of carbon deposits, paint films and sludge or to remove these deposits is called the detergency and dispersion of engine oil.
The hazards of carbon deposit to engine operation include:
one
Make the engine have an increased tendency to deflagrate.
two
The carbon deposit forms a high temperature source, which is easy to produce surface ignition, and can cause the engine power loss of 2% - 15%.
three
The carbon deposit between the spark plug electrodes will make the spark plug short circuited, resulting in reduced power and increased fuel consumption.
four
If the valve is not closed tightly, high temperature carbon particles will also cause the valve and valve seat to be ablated.
five
Carbon deposits enter the crankcase, causing deterioration of the lubricating oil and clogging of the filter.
Carbon deposit generation:
The carbon deposits cover high temperature areas such as cylinder heads, spark plugs, fuel injectors, piston tops, and other solid carbonaceous substances with large thickness.It is the deposition of smoke and other substances on high-temperature parts due to incomplete combustion or engine oil flowing into the combustion chamber at high temperature.
The hazards of paint film are:
one
Reduce the flexibility of the piston ring, or even cause the ring to stick, making the piston ring lose its sealing effect, resulting in power reduction.
two
The poor thermal conductivity of the paint film causes the piston to overheat, resulting in cylinder scuffing.
Formation of paint film:
The paint film is a kind of solid and shiny paint like film, mainly produced in the piston ring area and piston skirt.It is mainly the catalysis of hydrocarbons at high temperatures and metals.Resin, asphaltene, etc. generated by oxidation and polymerization under the action ofPolymer。
The factors affecting the formation of high-temperature deposits are: (carbon deposit and paint film belong to high-temperature deposits)
one
Design and operating conditions of the engine.
two
Nature of fuel and lubricating oil.
The hazards of sludge mainly include:
one
The engine oil will age and deteriorate, and the lubricating property will decline.
two
Block the lubrication system.
Sludge generation:
Oil sludgeIt is a relatively stable condensate of oil-water emulsion and various impurities. Cars running in the city stop and start from time to time, and the engine runs at low temperature for a long time, which is easy to produce oil sludge in the oil pan.
The factors affecting the formation of oil sludge are: (oil sludge belongs to low-temperature sediment)
one
Operating conditions of the engine.
two
Nature of fuel and lubricating oil.
The engine oil base oil itself does not possess detergency and dispersibility, but is obtained by adding detergents and dispersants.It is mainly evaluated through corresponding engine test.
Antioxidant
Under certain conditions, the ability of engine oil to resist oxidation and deterioration is called the anti-oxidation property of engine oil.
It determines whether the engine oil is easy to deteriorate in use, and the tendency to corrode parts and generate deposits is an important factor determining the service life of engine oil.
5) Good corrosion resistance:
The ability of engine oil to resist corrosion of metals by corrosive substances is called the corrosion resistance of engine oil.
Neutralization value is the index for evaluating the corrosion resistance of engine oil, which is evaluated through corresponding engine tests.
Antifoam
The anti foaming property of engine oil is called anti foaming property of engine oil.
When the engine oil is stirred violently and air is mixed into the oil, foam will be generated. If the foam is not eliminated in time, air lock, insufficient oil supply and other faults will occur.
The indexes for evaluating the anti foaming property of engine oil are foam inclination and foam stability.[2]
Relevant information
Announce
edit
Common mistakes
Myth 1: When the lubricating oil turns black, it's time to change it
This understanding is not comprehensive.For lubricating oil without detergent dispersant, blackening is indeed a sign of serious deterioration, butHyundai MotorGenerally, the lubricating oil used is added with tranquilizing decomposition agent.This tranquilizer washes the adhesive film and black carbon deposit adhered to the piston, and disperses them in the oil to reduce the generation of high-temperature deposits in the engine. Therefore, the color of the lubricating oil tends to darken after a period of use, but the oil is not completely deteriorated at this time.
Misunderstanding 2: Add more lubricating oil if you can
The amount of lubricating oil should be controlled between the upper and lower scales of the oil dipstick.Because too much lubricating oil will rush into the combustion chamber from the clearance between the cylinder and the piston to form carbon deposits.These deposits will increase the compression ratio of the engine and increase the tendency to produce knock;The carbon deposit in the cylinder is red hot, which is also easy to cause early combustion. If it falls into the cylinder, it will aggravate the wear of the cylinder and piston, and also accelerate the pollution of lubricating oil.Secondly, too much lubricating oil increases the mixing resistance of the crankshaft connecting rod, which increases the fuel consumption.
Misunderstanding 3: additives are of great use
The truly high-quality lubricating oil is a finished product with a variety of engine protection functions. The formula already contains a variety of additives, including anti-wear agents. The most important thing about lubricating oil is the balance of the formula to ensure the full play of various performances.Self addition of other additives can not bring additional protection to the vehicle, but it is easy to react with the chemicals in the oil, resulting in the decline of the comprehensive performance of the oil.
Mistake 4: Lubricating oil is often added but not replaced
It is correct to check the lubricating oil frequently, but only supplement without replacement can only make up for the shortage of oil quantity, but cannot fully compensate for the loss of lubricating oil performance.During the use of lubricating oil, the quality will gradually decline due to pollution, oxidation and other reasons. At the same time, there will be some consumption, which will reduce the quantity.
How to identify water in oil:
According to the regulations, the allowable water content in the engine oil should be below 0.03%.When the water content exceeds 0.1%, the additive of engine oilantioxidant、Detergent dispersantIt will be lost, thus accelerating the oxidation process of engine oil.The organic acid generated by oil oxidation and theAcid oxideReacts with water to form inorganic acids.These acids increase the corrosion of the engine.When there is more water in the engine oil, the lubricating property of the engine oil will become poor and the viscosity will decline, which will lead to premature deterioration of the engine oil and rusting of the parts;Serious mechanical accidents such as engine axle seizure and bush burning may be caused.
How can we identify water in engine oil?
1. Color observation method.The oil that is clean and up to standard is blue and translucent.Oil with water is brown.When the engine runs for a period of time, the oil is milky white with foam.
2. Combustion method.Heat the copper rod and put it into the engine oil to be checked. If there is a "crackle" sound, it means that there is more water in the engine oil.The engine oil can also be injected into the test tube for heating. When the temperature is close to 80 ℃ to 100 ℃, the test tube will produce a "crackle" sound, which indicates that the engine oil contains more water.
3. Drainage method.After the engine is stopped, let the engine stand for about 30 minutes and loosen the oil drain plug. If water is discharged, it means that there is more water in the oil.
How to select the oil with proper specification:
Since the engine oil has a great impact on the service performance and life of the engine, the engine oil of the same series, service grade and viscosity grade should be selected in strict accordance with the provisions of the vehicle operating instructions.The engine oil recommended in the vehicle manual is determined according to the engine performance and the temperature of the sales region. It has a certain guiding role in the selection of engine oil, and has a large safety factor. It is also one of the preconditions for claims within the warranty period of the engine.If there is no manual, the following methods can be used to select appropriate oil specifications.
1. Select the engine oil of the corresponding series according to the fuel used by the engine; select S series oil for gasoline engine;C series oil is selected for diesel engine;LPG engineSpecial engine oil for liquefied petroleum gas shall be selected.
Selection of engine oil service grade.Since the severity of gasoline engine working conditions is related to whether there are additional devices in the engine intake and exhaust systems and their types, the use grade of gasoline engine oil can be selected according to the type of additional devices.
① Without attachmentsgasoline engineSD grade oil can be selected.
② SE grade oil can be selected for gasoline engines with positive crankcase ventilation (PCV) device.
③ For gasoline engines with exhaust gas recirculation (ECR) system, SF grade oil shall be selected.
④ Withcatalytic converter For gasoline engines with middle and low grade EFI system, oil above SG level shall be selected.
⑤ For usingnew materials For medium and high grade EFI gasoline engines with new technology, SJ or above engine oil shall be selected.
In addition, the use grade of gasoline engine oil can also be roughly distinguished according to the production year for vehicles imported from Europe, the United States, Japan and other automobile producing countries.For example, SG grade oil was used from 1989 to 1993;1994-1996 SH grade oil;SJ grade oil used from 1996 to 2001;SJ or SL grade oil has been used since 2001.This is because the later the production year of the car is, the more its performance will be improved, and the working conditions of the engine oil are usually stricter than those of the cars produced in earlier years.
2. Selection of diesel engine oil service grade.
The use level of diesel engine oil shall be determined according to the enhancement coefficient of the diesel engine, which represents the sum of the mechanical load and thermal load of the engine.
3. Selection of viscosity grade
The selection of oil viscosity shall meet the requirements of low temperature starting property and high temperature lubricity at the same time.Select viscosity grade according to region, season and temperature, and try to use multi grade oil.The engine oil used in winter in severe cold areas shall be OW, 5W oil or OW/20 or 5W/20 multigrade oil;In summer in hot areas, 40 # oil or 20W/40 # oil should be used.
The viscosity grade shall be selected according to the technical characteristics of the engine.For new engines, oil with low viscosity shall be selected to ensure normal running in during the service life;For engines that have been used for a long time and are subject to heavy wear, oil with high viscosity should be selected to maintain the required oil pressure and ensure normal lubrication.
Cause analysis of excessive oil consumption of diesel engine:
When the engine is working, the cylinder wall, piston ring and piston are full of oil. When the fit clearance between the three is abnormal, the oil between the cylinder wall and piston will enter the combustion chamber, which is the main reason for oil leakage.After the engine works for a certain time, the radial dimension of the piston ring decreases, the elasticity decreases, the opening clearance increases, and the sealing and oil scraping functions become worse.The clearance between the piston ring and the ring groove increases, strengthening the oil pumping effect of the piston ring. When the piston moves upward, the oil is scraped into the combustion chamber.Carbon deposition is easy to occur after oil channeling, accelerating cylinder wear and forming a vicious cycle.After the piston ring is stuck, the engine oil is burned. When the piston ring is stuck in the ring groove, the piston ring loses its elasticity and the seal becomes poor. Not only does the piston carry a large amount of engine oil into the combustion chamber when it goes up, but also a large amount of high-pressure gas flows into the crankcase when the piston does work, increasing the pressure in the crankcase. The splashed engine oil enters the air inlet through the crankcase ventilation device,Let the oil and air enter the combustion chamber together for combustion.
When foundCrankcase ventilationThe device has serious gas leakage, which is mostly caused by piston ring clamping, and should be eliminated in time.The overhaul quality of the engine has a great impact on the oil leakage of the cylinder. The roundness, cylindricity error and surface roughness of the cylinder are too large, the piston ring is not matched with the piston according to the technical requirements, the piston deflects the cylinder during assembly, and the perpendicularity of the cylinder center line and the crankshaft rotation center line exceeds the specified requirements.At the same time, the piston carbon deposit is not cleaned, the piston ring is installed reversely, the ring mouth is not reasonably distributed, and the gap between the ring mouths is too large, which will accelerate the cylinder oil leakage to varying degrees.Oil leakage occurs soon after the engine runs, partly due to unqualified piston rings.Many piston rings sold on the market have quality problems, such as insufficient elasticity and poor elasticity durability, which can not adapt to the deformation of the cylinder liner. This is the main reason for oil leakage in the cylinder after a certain mileage.
Replacement procedure
At present, some young car owners are more and more familiar with cars and are more willing to DIY for many things about their cars.Self oil change is very popular in Europe and the United States. Many videos about how to change the oil can be seen on the Internet. Here's how to change the oil yourself.After selecting the appropriate oil, you can start to do it yourself. The specific steps are as follows:
Step 1: Run the engine to reach the operating temperature.Then uselifting jackJack up the vehicle, pull up the hand brake and wedge the front wheels.
Step 2: Place an old oil container under the oil pan, find the oil drain bolt of the oil pan, and slowly tighten it to drain the oilBoltBe careful not to touch the hot oil.Allow the oil to drip for a while.Check the oil drain bolt, reinstall the oil drain bolt, and be careful not to tighten the bolt too tightly to prevent damage to the oil pan.
Step 3: Move the oil container below the oil filter and useOil filterLoosen the filter element with a wrench, and then unscrew it by hand.Iffilter elementIt's still hot. Remember to wear gloves.Even if the filter element is tightened before, you don't have to worry about damaging the filter element during removal, as long as you don't damage the interface screw for installing the filter element and the components around the filter element. After all, the removed filter element is no longer used.
Step 4: select the appropriate oil filter element according to the user's manual.
Step 5: Coat the interface of the new filter element with new engine oilWasher。If the installation position of the filter element is vertical, some new oil can be poured into the filter element to reduce dry grinding at the next engine start.Screw in the filter element by hand, and tighten the filter element according to the indicated method (usually screw in 3/4 of a turn after manually tightening the filter element).
Step 6: pour new oilOil panPlease refer to the user manual.A funnel can be used to prevent oil from being poured outside the engine.Check the lower part of the engine for leaks.If there is no leakage, put the vehicle down and checkOil dipstick, and start the engineOn instrumentThe indicator light of should go out immediately.Finally, switch off the engine and recheck the oil quantity, and dispose of old oil andfilter element。
quality guarantee period
The simplest way to check the warranty period of automobile oil is to observe whether the viscosity of the oil changes, judge whether the smell of the oil fades, and observe whether the color of the oil changes.When observing the change of oil color, pay attention to the change of additives in the oil.In addition, filter paper or electronic instrument can be used to check whether the warranty period of automobile oil has passed.
The engine oil is sensitive to moisture in the air, ambient temperature and light. If it is exposed to strong light for a long time, it will usually fail.The use of engine oil after the warranty period will cause great damage to the automobile engine, such as poor lubrication effect, and the cooling effect will also be affected.
I believe many car owners will maintain their cars regularly.When doing maintenance, replace the engine oil and oil filter, make sure the car does the necessary things for maintenance.First, let's understand the importance of these two things.
1. Oil is the lubricating oil for engine operation.It can lubricate, clean, cool, seal and reduce wear of the engine.It is of great significance to reduce the wear of engine parts and extend their service life.
2. The engine oil filter is a component for filtering engine oil.Oil contains a certain amount of gum, impurities, moisture and additives;In the process of engine operation, the metal chips generated by friction of various components, impurities in the air inhaled, oil oxides, etc. are all the objects filtered by the oil filter element.If the engine oil is not filtered and enters the oil circuit directly, it will adversely affect the performance and life of the engine.
Many car owners sometimes maintain their cars according to the mileage they have driven.In fact, the maintenance time depends on the effective time or mileage of the oil used and the oil filter element.The validity period of mineral oil, semi synthetic oil and fully synthetic oil of different brands and grades is also different. Please refer to the manufacturer's recommendation.The oil filter element is generally divided into conventional and long-acting ones. The conventional oil filter element is replaced with the oil, and the long-acting oil filter element has a longer service life.
True false discrimination
First, it depends on the appearance of the package. The famous brand oil seal cover is a disposable cover. There is sealing tin paper at the notch, and the tin paper has special marks from the manufacturer. Without these characteristics, it may be fake oil.In addition, in order to prevent counterfeiting of famous brand oil, there are special marks on inconspicuous places such as label stickers, tank bottom, inner side of tank cover, handles, etc. If the criminals customize the packaging for counterfeiting, they can be distinguished by comparing the two outer packages.
The second is to observe the oil products. The real oil is light and transparent, free of impurities, suspended solids and sediment, and has good fluidity when shaking.False oil or oil color is deep, or there are impurities and precipitates, or the taste is strong and irritating, and the fluidity is poor when shaking, or there is wire drawing when touching.
There are generally three types of counterfeit oil products:
First, the recycled waste oil is filled and listed after treatment;
The second is to use pure base oil mixing without any additives;
The third is to buy low-grade oil for filling and replace the defective oil with the good one.Generally, the color of fake lubricating oil is adjusted to match that of real oil.[3]
