In recent years, the number of car owners has gradually increased, and the car needs regular maintenance, but some of the limited maintenance centers often go into maintenance mistakes and affect the performance of the vehicles. There are 10 main performances:

　　1. The bearing shell of sliding bearing must be shaved. And modern automobile, especially small motor, its crankshaft bearing and connecting rod bearing, bearing the wear-resisting alloy coating is very thin, will not allow to be scraped, can only press corresponding dimensions to match. If there is no suitable size of curved bearing, it is necessary to grind the crankshaft with the method of the base hole to find the proper fit clearance.

　　2. The engine is not afraid of high water temperature. In fact, the low water temperature of modern automobile engines is very harmful, which will make the mixture combustion not sufficient, the power will be reduced, the oil consumption will increase, and the lubrication will be caused, and the emission will be exceeded.

　　3. The clearance of valve gap is stronger than smaller point. In fact, the valve gap is large, the valve lift is not enough, the air intake is insufficient or the exhaust is not good, the engine power is reduced precisely.

　　The more oil you have, the better. In fact, the engine oil adds more to the engine, as well as the slanting engine and v-type engine. It increases the rotation resistance of crankshaft and connecting rod, and increases the oil splashing on the cylinder wall, resulting in an increase of combustion chamber carbon. So more oil, less engine power, more wear, more emissions.

　　5. Air hub lubrication is not reliable. It is believed that the wheel hub is filled with grease, which can guarantee the lubrication of the hub bearing, which can only be used to lubricate the empty hub of the bearing, so that the space between the hub should be filled with grease. In fact, it not only wastes grease, but also affects the heat dissipation of the bearing, which is harmful to the lubrication of the bearing.

　　6. The braking of the brake is a sign that the wheel is dead, and the modern car just requires the wheels to be unable to hold the dead, so the anti-lock device is specially installed. Once the wheels are dead, the steering failure of the car, the wheel slip, can easily malfunction, so it is not the longer the better.

　　7. Small gaps between the contact points of the breaker are good. In fact, the contact gap is too large, and the closing time of the contact point is short, so that the current of the ignition coil is reduced at one time, resulting in the weak high voltage, which makes the engine not easy to start.

　　8. Advance Angle of ignition and advance Angle of spray oil. The engine generates explosion, which damages the piston greatly and seriously affects its service life, and the starting resistance of the engine increases.

　　Tighten the fastening bolts and tighten not loose. In fact, bolts of all parts of the car have corresponding regulation values according to diameter, pitch and use, and the size of tightening torque. It is not good to get the bolts that fall short of the regulation value, but blindly increasing the tightening torque will deform the fastening parts and cause the bolt elongation, thread deformation and even fracture.

　　10. It is easy to disassemble the inspection when the car is maintained. With the improvement of manufacturing level, the life of modern car parts has been greatly extended, and random disassembly is bound to destroy the state of coordination. In this day, if there is no obvious failure of the parts or assembly, the inspection should not be taken apart.