Recently, the temperature across the country began to drop sharply. With the temperature gradually breaking below 0 ° C in some areas, it is time for diesel engines to be filled with winter oil. So what measures and points for attention should be taken when using engine oil in winter?
Methods & steps
Select the oil viscosity according to the operating ambient temperature
Diesel engine oil is classified according to two different classification methods: different viscosity grades (low temperature viscosity grade and high temperature viscosity grade) and oil quality grade. The viscosity grade adopts the rating standard of American Society of Automotive Engineers (SAE). The oil quality grade adopts the rating standard of American Petroleum Institute (API). Viscosity grade is generally used to distinguish in domestic market.
The viscosity grade is generally marked by the working temperature range that the oil can adapt to. For example, SAE40 and sae50 engine oils are summer engine oils. The applicable temperature is 40 ℃. They are only used in summer and cannot be used in winter; SAE15W-40 and sae5w-40, which are labeled as general-purpose engine oils, can be used normally at ambient temperatures ranging from minus 30 ℃ to 40 ℃.
"W" in the engine oil label indicates winter. The more obvious the figure in front of it, the better the low-temperature fluidity of the engine oil, the lower the usable ambient temperature, and the better the protection ability of the engine during cold start; The number behind "W" (behind a horizontal) is the index of high temperature resistance of engine oil. The larger the value, the better the protection performance of engine oil under high temperature.
The selection of appropriate oil viscosity has a direct impact on the working performance of the engine, which is mainly reflected in the following two points:
(1) Although the oil with high viscosity has strong adhesion, high viscosity will increase the internal load of the engine and cause large internal power loss of the engine.
(2) Although the oil with low viscosity can reduce the wear and friction of moving parts and improve the self-cleaning ability of the engine, due to the low viscosity of the oil, even if the oil reaches the working temperature, the oil pressure is low or even cannot reach the working pressure due to the too thin oil, which will lead to insufficient lubrication and aggravate the wear of the engine, which is likely to be damaged by the cylinder pulling and bearing of the engine.
The following is an example to explain how to choose the right winter oil.
For colder areas such as Beijing, it is sufficient to fill the commonly used 15w-40 general engine oil (when the ambient temperature is - 15 ° C to 40 ° C); For Northeast China and other Alpine regions, it is necessary to consider changing the engine oil with higher grade in winter, such as 10W-30 engine oil (used when the ambient temperature is minus 10 ° C to 30 ° C), or engine oil with higher grade; For the warmer areas in the south, we can consider whether we need to change the engine oil with different grades according to the actual local conditions.
Select the oil quality according to the engine grade
At this stage, Chinese construction machinery manufacturers mostly use four stroke turbocharged direct injection engine to assemble on their own equipment, and the emission standard only reaches the second stage emission (i.e. tier-2). CF-4 grade engine oil is selected for the model equipped with this kind of engine to ensure normal use.
For diesel engine oil used in construction machinery, such as CF-4 grade oil, where C represents special oil for diesel engine; F stands for the quality grade. The performance of engine oil will be better than that of the previous one with each increasing letter. The later the letter is, the higher the quality grade is; "- 4" indicates the performance improvement grade of engine oil. In the same grade of engine oil, the larger the number, the better the quality.
For imported models, when selecting engine oil, it needs to be selected according to its engine oil supply mode: CF-4 grade engine oil can be selected for direct injection supercharged engine; The EFI supercharged engine needs to select CH-4 grade or higher oil to ensure the normal operation of the engine.
At the same time, the engines adopted by most domestic construction machinery manufacturers do not use exhaust gas recirculation system, i.e. EGR. Therefore, selecting CF-4 or CH-4 diesel engine oil can meet the requirements of engine oil for construction machinery in the domestic market at this stage.
Special reminder: if the equipment purchased by users is not sold directly to the Chinese market, it is necessary to accurately judge the engine emission standard to select the required engine oil.
Since the diesel engine with the third stage emission standard has been widely used in the models sold by construction machinery manufacturing enterprises to countries and other regions in the world, users should choose the appropriate quality grade of engine oil when purchasing the required engine oil, so as to avoid harm to the engine. Precautions for oil filling
Filling the engine oil is a simple thing for anyone, but there are still a few points to pay attention to when filling the engine oil.
1. It is forbidden to mix oils with different grades.
In winter, if the equipment needs to change the oil with different grades, it is necessary to drain all the oil in the engine before adding the oil with a new grade.
2. It is forbidden to mix different brands of engine oils.
Different brands of engine oils will use different additive formulations. Mixed use may produce chemical reactions, reduce the service performance of engine oils and affect the normal operation of the engine.
3. Drain the engine oil.
Before replacing the old engine oil, start the engine and idle for a certain time to make the engine oil temperature close to the working temperature, and then replace the old engine oil.
There may be many friends who don't understand the heat engine oil. In fact, it is because the hot engine oil has strong fluidity and can effectively clean up the impurities attached to the body surface. The oil discharged by this method will effectively reduce the amount of residual impurity particles in the engine, reduce the wear of the engine and ensure the efficient operation of the engine. In addition, the hot oil is easier to discharge completely and reduce the residue of old oil.
4. Do not "add a little more" for oil filling.
Generally speaking, it is good to add the engine oil to a little above the center line of the engine oil scale (about 3cm). Excessive oil will increase the resistance of crankshaft rotation. Moreover, due to the advent of winter, the low temperature will increase the oil viscosity, and the excessive crankshaft rotation resistance will reduce the engine power, resulting in the weak action of the whole equipment.
In addition, the excessive addition of engine oil will also increase the possibility of engine oil channeling, which is very easy to cause the increase of engine oil consumption (commonly known as blue smoke), increase the carbon deposition in the combustion chamber, increase the probability of deflagration, affect the normal operation of the engine and cause unnecessary wear of the engine. Therefore, the oil must be added to the specified position, that is, a little higher in the middle of the scale line of the dipstick, which is enough.
In addition, before adding engine oil, it is also necessary to clean the filler and oil barrel to prevent impurities from entering the engine body. After filling the engine oil, we also need to wipe the spilled engine oil to maintain a good working environment of the engine. These are the details that we need to pay attention to when carrying out daily maintenance on the engine.
Above, we briefly introduced the engine oil in the winter maintenance of the engine. In the cold winter, if the machinery can be well maintained and maintained, whether in the winter construction operation or the long-term parking during the winter break, we will know well and spend the winter with ease.
