How to judge the quality of a car by the sound of its engine?

Hello, four sounds of automobile engine failure:

The engine hisses, just like steam or air coming out of the engine. Generally, after hearing this sound, the engine will lose power quickly. Possible problem, engine overheating, check the cooling system. The exhaust system is blocked, and the vacuum tube leaks or breaks. The engine has a kicking sound, like the sound of a pencil knocking on a table. As the engine speed increases, the sound increases. Possible cause: there is dust in the engine part. It is recommended to change the oil, filter the engine and clean the engine. There may be a valve problem. When the engine is changing its speed, it will make a clicking sound, as if something is beating the metal. You may not hear it when you speed up, which may be due to the cylinder valve. Adjust the valve to change it. Lack of oil may also cause similar problems, and the oil pressure is relatively low, so it is necessary to check the oil pressure.

The engine will whir when accelerating, or it will appear when decelerating. In short, as the speed changes, the volume will also change. Possible cause: the power steering oil is insufficient and filled with oil. The generator bearing may be damaged. When there is a problem with the power steering pump and water pump, it will also produce similar noise.

Method for judging the quality of automobile engine;

First, look at the whole.

Look at the appearance, first of all, check the external cleanliness of the engine to see if there is too much dust to determine whether it is excessively worn. However, we must pay special attention. If it is spotless, it doesn't mean that the car wears little. Or maybe the owner did something to cover up some information. Next, it depends on whether the gap around the hood of the used car is consistent, and whether the gap between the fender and the hood and the windshield is consistent. These nuances are the criteria for considering engine quality. It should be noted that the detection of range hoods is the most important. If there are paint marks on the hood side or the shape and size of spot welding are inconsistent, the vehicle is likely to have an accident.

Second, look at the oil

Oil level and color are also factors that need to be monitored. If the oil level is too high, it means that the engine is leaking seriously. During the inspection, it is also necessary to observe the bottom of the filler cap after unscrewing it. For example, there is a thick dark emulsion at the bottom of the oil filler cap, and there are small water droplets mixed with oil pollution, which is likely to damage the cylinder gasket, cylinder head or cylinder block. Everyone must choose carefully.

Third, look at the belt.

The function of each belt on the automobile engine is also very important, so when buying a used car, if the belt is seriously worn, as long as it is pressed hard, the belt will sink into the groove of the pulley, and then a new belt must be replaced in time.

I hope I can help you!