There may be the following reasons for the cracks in the automobile intake pipe:

1. High temperature and expansion with heat and contraction with cold: when the automobile engine is running, high temperature will occur, and the intake pipe will expand with heat and contract with cold in a high temperature environment for a long time, which will lead to the deformation and stress concentration of the intake pipe material and may eventually cause cracks.

2. Vibration and vibration: When the car is driving, it will be shaken and bumped by the road surface. Long-term vibration and vibration will lead to uneven stress on the intake pipe, which will lead to fatigue cracking of the intake pipe.

3. Collision and damage: In the process of automobile repair or maintenance, if you accidentally collide with the intake pipe or use improper tools to cause damage, it may lead to cracks on the surface or inside of the intake pipe.

4. Corrosion and corrosion: Long-term exposure of the intake pipe to humid or chemically corrosive environment may lead to corrosion and corrosion of the intake pipe materials, and eventually lead to cracks.

5. Excessive pressure: If the intake pipe system is improperly designed or installed, it may cause the intake pipe to be subjected to excessive air pressure or vacuum pressure, resulting in deformation and cracks of the intake pipe.

To sum up, the causes of cracks in the automobile intake pipe may include factors such as high temperature, thermal expansion and contraction, vibration and vibration, collision and damage, corrosion and corrosion, and excessive pressure. In order to avoid cracks in the intake pipe, it is necessary to check and maintain the intake pipe system regularly to ensure its normal operation and safety.