Why does the Santana Vista's water pipe get blocked after the engine is turned off?
2 Answers
This situation is normal due to the thermal expansion and contraction phenomenon. After the engine is turned off, the car cools down and the water pipe contracts accordingly. Function of the drain hole: The purpose of the air conditioning drain outlet is to continuously absorb moisture from the surrounding air during air conditioning use. During the heat exchange process, the moisture condenses into water through the air conditioning drain groove and is discharged through the drain outlet. Drain pipe issues: Common problems with car air conditioning drain pipes include aging, loosening, or bending into a wavy shape after long-term use, which can cause poor drainage and local blockages. The solution is to contact the manufacturer or a qualified air conditioning repair technician to replace the drain pipe.
I also encountered this situation when I first drove my Zhijun. After turning off the engine, the water pipe suddenly became hard and swollen like a balloon, which was quite frightening. Later, I found out that it was mostly caused by residual high temperature and water pressure in the engine after shutdown, which wasn't fully released. The reasons could be air bubbles trapped in the cooling system or the pressure valve of the radiator cap not opening, leaving the pressure with nowhere to go. In some older cars, an aging water pump can also cause this, leading to poor circulation. I also checked related information and found that it's more likely to happen after driving on the highway in hot weather, so don't rush to check immediately after parking—wait until it cools down completely to avoid burns. If it happens repeatedly, it's best to take some time to visit a professional repair shop to bleed the system and replace some new coolant, which can protect the system from damage. Safety always comes first—don't push through and keep driving.
