In many cases of automatic transmission maintenance, shift impact is common. Automatic transmission has been used for a long time, and shift impact often occurs. If this happens, it must be repaired in time to avoid danger in driving.

車主黃先生：我的車已行駛25000公里，我發現冷車啟動到熱車，當發動機轉數達到1000，剎車踩緊時，掛D擋起步時阻力較大，掛R擋時有較大沖擊感。請問這是什么原因？

Owner Mr. Huang: my car has driven 25000 km. I found that when the cold car starts to the hot car, when the engine speed reaches 1000 and the brake is pressed tightly, the resistance is greater when I start in D gear, and there is a greater sense of impact when I shift into R gear. What is the reason?

專家出診：自動擋車型，理論上掛擋都會有沖擊感，D擋與R擋一樣。若兩者沖擊感不同，則有

Expert visits: in theory, automatic models have a sense of impact when they are in gear. D gear is the same as R gear. If the impact of the two is different, there is a difference

車主黃先生：我的車已行駛25000公里，我發現冷車啟動到熱車，當發動機轉數達到1000，剎車踩緊時，掛D擋起步時阻力較大，掛R擋時有較大沖擊感。請問這是什么原因？

Owner Mr. Huang: my car has driven 25000 km. I found that when the cold car starts to the hot car, when the engine speed reaches 1000 and the brake is pressed tightly, the resistance is greater when I start in D gear, and there is a greater sense of impact when I shift into R gear. What is the reason?

專家出診：自動擋車型，理論上掛擋都會有沖擊感，D擋與R擋一樣。若兩者沖擊感不同，則有可能是發動機前后防震墊損壞層度不同和變速箱內部故障造成的。另外，較大沖擊感有可能是發動機轉速太高造成的，變速器的動力傳遞是由發動機轉速決定的。

Expert visits: in theory, automatic models have a sense of impact when they are in gear. D gear is the same as R gear. If the impact feeling of the two is different, it may be caused by the different damage layers of the front and rear shock pads of the engine and the internal fault of the transmission. In addition, the greater impact may be caused by the high engine speed, and the power transmission of the transmission is determined by the engine speed.

異響

Abnormal noise

車主趙先生：近幾天，我的車在涼車啟動時，感覺在A柱附近有嗒嗒的聲音，特別是在顛簸路段，聲音特別大。車熱了之后，聲音消失，請問這是什么原因？是不是氣溫太低引起的呢？

Owner Mr. Zhao: in recent days, when my car starts in the cold, I feel that there is a rattling sound near the A-pillar, especially in the bumpy road. After the car is hot, the sound disappears. What's the reason? Is it caused by the low temperature?

專家出診：如果響聲與溫度變化有關，就應屬發動機配氣機構的冷響，這種冷響是隨汽車行駛里程(5-10萬公里)的增加，而逐漸出現的，也是正常的自然磨損過程中出現的異響。另外，根據趙先生所說的情況，顛簸路段，聲音特別大，則有可能是A柱附近部件松動造成的，與溫度無關。

Expert visit: if the noise is related to temperature change, it should be the cold noise of engine valve train. This kind of cold noise gradually appears with the increase of vehicle mileage (50000-100000 km), and it is also the abnormal noise in the process of normal natural wear and tear. In addition, according to what Mr. Zhao said, if the noise is particularly loud on bumpy road sections, it may be caused by loose parts near the A-pillar, which has nothing to do with the temperature.