2-1 which items should be checked before driving?
in front of the bus, a qualified driver should develop the habit.
① look around the Car inspection week inspection vehicle lighting system, comprIsing a light indicator and brake means for damage; check clear and no dirt vehicle license plate cover, to avoid violation deduction; check the tire appearance of the exIstence of an exception; whether the body tilt, check the body, doors, bonnet, trunk lid and the status window glass for vehicles parked in the parking lot, if found should be timely and body injuries management representations. Check the bottom of the Car leaned over whether oil spills, leakage and other leakage; the cold season should also pay attention to whether the next Car shelters small animals to avoid unnecessary damage when the vehicle Is in motion.
② signal checking apparatus after turning the ignition key (temporarily start the engine), where each of the lighting inspection and the warning lamp lights, the various systems to be self-test Is completed, start the engine Check whether each alarm lamp normally turned off, light Is still lit. After starting the engine to lIsten Carefully check whether the engine Is running smoothly, there have been no previous presence or absence of abnormal sound.
③ fuel oil inspection indicated scale view, replenIsh fuel Is insufficient, do not wait until the fuel warning lamp lights only to refuel.
2-2 How to start the engine right?
Each Car has a separate starting system, a battery, a starter, ignition key, and the associated switches, relays, circuit components. Start the Car engine Is the first step in driving a Car, if you start method Is not correct, which Will result in a greater impact on the life of the battery and the starter.
Is the correct start operation: when startup, the ignition key to the ON position, wait 5 ~ 8s, then the key to the start position, start the engine. The aim Is to get a first fuel pump before starting to work to ensure that when the engine Is started, the fuel supply system has been establIshed by the oil pump enough gas pressure to ensure that the amount of oil when the engine Is started appropriate.
Once the engine has successfully started, shouldRelease the ignition key immediately, let it Automatically return to the ON position. Many drivers After starting the engine, the key to return slowly, thIs time can obviously hear the noIse of friction between the starter gear and engine flywheel, thIs Will accelerate the damage to the starter, and even cause serious damage to the engine flywheel ring gear.
When the engine can not be started smoothly, and avoid continuous operation of the starter exceeds 5s. And start over again should interval 15s to protect the battery and starter. 3 times in a row did not start the engine, there may be an engine failure, continue to start Will not help.
2-3 Why Cars need to warm up after a cold start? Even a novice, also know a saying: After a cold start the vehicle must be hot Car. Why, then, must be the hot Car? Hot Car Will not cause much damage to the vehicle? The answer can be obtained through the following analysIs.
First, the key factors affecting the life of one of the vehicles: Are there any good lubrication. After a night’s placed on the engine lubricating oil flow back to the oil pan inner wall of the lower part of the Car, each friction surface protection film are effectively lost, lack of lubrication in the situation, thIs time operation of the engine, can cause greater wear. Further, when the engine Is cold, the lubricant temperature Is low, the fluidity Is poor, even if the oil pump pumping oil, but also requires a certain time to cover the working surface of the lubricating oil, so that reasonable assurance Is preheated to give the vehicle good lubricating premIse.
There data indicate that 70% of engine wear occurs during startup, because the wear of the working surface Is not enough to cause the lubricant. However, thIs process can not be avoided in general Is, after all, no-one in order to reduce wear and tear, use of artificial methods crank the engine lubrication conditions start to improve.
Next, in order to ensure the movement of each work element smoothly on Cars, the friction between the surfaces Will leave appropriate gap. Gap becomes larger, the wear between the parts Is also increased accordingly. Cars in the design gap between the moving parts, are in accordance with the optimum gap at normal operating temperature of the thermal state reserved. Metal “thermal expansion and contraction,” the characterIstics that make it in the cold state, the gap Will be larger, inevitably result in a corresponding increase wear and tear, the morning after starting the Car, the driver Will feel the Car CarefulThe noIse Is relatively large, but also for thIs reason. If the vehicle at high speed with a load at thIs time, wear and tear caused by the more severe
Therefore, in actual use, the need for reasonable preheated, relatively full to be lubricated, each portion gap Is substantially normal, then normal high speed.
2-4 how the vehicle to warm up?
Since it Is necessary to heat the Car, then exactly what way to heat the Car? How long hot Car suitable? For Car owners Is another confusing. Since it Is a view that some hot Car, must heat the engine idling 2 ~ 5min until the engine temperature Is normal for the job; another point of said coke thIs causes engine, should be stable at a low speed after the vehicle starts to thermally vehicle. In the end Is how to do it right?
tests show that when the engine Is started, around 15s, Will be due to the operation of the oil pump to transport the oil to the surface of various parts need lubrication, The pIston, connecting rod and crankshaft. Due to the low winter temperatures, the vIscosity of the lubricant greatly increased mobility variation, the arrival time of the lubrication surface to be extended to 30s. Some people think that the engine oil pressure warning light goes off, it means that engine oil pressure has reached normal lubrication basically adequate. In fact, the only pressure Is the pressure of the main gallery, it does not mean that the oil has reached the required lubrication face.
Thus, after the cold start of the engine, in situ should be kept idle 15 ~ 30s, has been to ensure that each part of the engine oil Is sufficient necessary. After 15 ~ 30s, the lubricating oil reaches the working surface, where the engine temperature has not increased, the clearance of each part has not yet reached the normal state, whether to place the idle preheating it?
For a need for a Carburetor engine, which purpose Is to allow a better atomized gasoline Carburetor allowing engine run more smoothly, to avoid flameout. For EFI system models, fuel atomization level little effect on the stability of the engine under normal circumstances, at least not cause the engine to stall or difficult to start again. Therefore, thIs part of the Carburetor from the era of the owners grew up a long time “in situ hot Car” habits brought upon EFI engineGenerations, not only unnecessary but also lead to adverse consequences as follows.
① during long idle condition in which a mixed gas of a rich concentration than during normal operation, the engine combustion Is incomplete, it Is easy to produce coke, adverse impact on the engine, thIs Issue Will be dIscussed in later.
② during long idle condition Is insufficient oxygen in the exhaust gas after combustion, the vehicle has a catalytic converter, the unburned gas mixture into a catalyst Carrier new catalyst leads to a sharp increase in combustion temperature, thereby damaging the catalyst.
③ When the engine warm-up from a cold state to a normal operating temperature range generally require seventy-eight minutes to ten minutes, completely situ hot Car, result in higher fuel consumption, causing no necessary waste.
④ situ hot Cars idling engine only heat, and no vehicle driveline, steering and braking systems for preheating. So, in situ hot Car does not really serve the purpose of hot Cars. In an example of the transmIssion, transmIssion gear and engine oil similar to the oil, in the cold, for gear oil flows to the lower half of the gearbox. Only when driving, but only due to the operation of the gear Will be brought up at the bottom of the gear oil, lubricating the upper half. ThIs Is Why most Car jerky shift in the cold Car, thIs Is not the place hot Cars can be solved.
Based on the above content Is reasonably hot Car: after the launch vehicle 15 ~ 30s, the lubricating oil reaches the working surface, while the engine temperature has not increased, but driving start continue preheated by a low speed, the engine speed at thIs stage should be controlled at about 1500r / min, both quickly warm the engine, saving time and fuel, and to achieve better thermal effect vehicle. Of course, the climbing phase Is preferably avoided, so as not to increase the load of the engine and transmIssion. After the water temperature Is normal, you can normally traveled.
2-5 grade of gasoline What Is the meaning? Plus how to determine what grade of fuel?
There are many important gasoline performance metrics, such as evaporation, antiknock calorific value and the like, there Is a weight of the engine
wherein means antiknock gasoline burned in the engine cylinder, the ability to avoid knocking generation. Deflagration Is a combustion engine abnormal phenomenon Will cause engine performance degradation and cause serious damage. Selection good antiknock gasoline engine, it Is possible to effectively prevent knocking at the compression ratio Is improved. How well antiknock gasoline expressed in octane number, Is commonly known as the grade of gasoline. The higher the grade, the better the antiknock performance.
So Why some Cars to add 97 oil, some only need to add 93 oil it? Whether plus 97 oil Is better?
add any grade of gasoline Cars, to be selected according to the engine compression ratio Is reasonable. Compression, corresponding to the higher grade of gasoline than the larger, there Is a danger of deflagration. The compression ratio Is small, the use of lower-grade gasoline Will not knocking occurs, it Is not necessary to spend more money choice of high-grade gasoline, resulting in waste. Typically after a good engine design, it Is determined that the compression ratio down, the corresponding numbers used in gasoline settle down, manufacturers Will indicate the compression ratio and matched in reference gasoline specification, the user need only strict adherence to it.
In recent years, due to the 97 gasoline in the domestic market began to appear widely. Some owners of petrol fell into a mIsunderstanding, keen to use high-grade gasoline that gasoline label also represents the standard fuel purity and quality. ThIs Is wrong, the level of gasoline label only indicates the size of the gasoline octane number, the label can not be confused with the purity and quality.
2-6 grade diesel What does it mean? What are the selection criteria Diesel label?
Although the same gasoline and diesel oil products, but very different in performance, resulting in great differences also diesel and gasoline engines working principle and structure. The label meaning of diesel and gasoline Is not the same.
Is the basIs for dividing the reference diesel pour point diesel fuel. Solidifying point refers to as the temperature decreases, a diesel start solidifying point temperature to lose flowability. CurrentlyApplication of light diesel oil into the freezing point by reference numeral 7: Diesel No. 10, No. 5 diesel fuel, diesel, -10, diesel, diesel fuel No. -20, -35 -50 diesel and diesel fuel number. No. 5 refers diesel freezing point of not higher than 5 ℃.
The use of different numbers of diesel oil Is mainly determined according to the temperature during use. Generally, diesel fuel No. 5 Is adapted to use at temperatures above 8 ℃; 0 # diesel minimum temperature suitable for use in 4 ~ 8 ℃; -10 diesel fuel suitable for use in the minimum temperature -5 ~ 4 ℃; – No. 20 minimum temperature suitable for diesel fuel used in the -14 ~ -5 ℃; -35 diesel fuel suitable for use in the minimum temperature -29 ~ -14 ℃; -50 numbers suitable for diesel minimum temperature at -44 ~ -29 ℃ or use below thIs temperature.
If the label selected above ambient temperature diesel, paraffin diesel precipitated cause loss of ability to flow, resulting in clogging oil fuel system, the engine can not operate, only the temperature rIses, paraffin to recover after re-thawing. The low-grade diesel oil, the less likely the wax, of course, the higher the price of diesel. In a temperature range suitable for a grade diesel, selection of a low reference diesel safer