The luxury car I bought for more than 2 million yuan actually leaks. Why would a new car leak?

Recently, a piece of news attracted a lot of attention. A car owner said that he spent 2.15 million yuan to buy a car of a certain brand. After picking up the car, he found that there was an abnormal noise in the car and the A-pillar interior was leaking. After many rounds of negotiations with the 4S store, the owner failed to reach a consensus on compensation. The owner sealed the roof of the car with tape and three-color rain cloth, and posted photos and videos on his personal social account. This move made the matter widely circulated and also triggered many owners of the same brand to imitate, and they also glued a three-color snakeskin cloth rainproof blanket on the roof of their cars.

Image source: a social platform

Many friends may ask, why is the quality of luxury cars so poor? Why does a good new car leak? What should we do after the leak? How to prevent car leaks?

Quality issues with million-dollar luxury cars?

How could such an expensive car have quality problems?

According to the 2024 China Initial Quality Study (IQS) report, the luxury brand's average PP100 score is 213, slightly lower than the mainstream brand's average score of 211. PP100, or the number of problems per 100 vehicles, is a measure of vehicle quality, with lower scores indicating fewer vehicle problems and higher reliability.

In other words, the brand involved in the "three-color tarpaulin" incident, although a luxury brand, has a higher number of problems with its vehicles than some mainstream brands.

So why does this happen?

A car is an industrial product. Whether it is a luxury car or a cheap car, it is produced on an assembly line. A car is made up of tens of thousands of parts. At the same time, the design of a car involves many disciplines such as mechanical engineering, electrical engineering, and materials science. It also requires interdisciplinary cooperation and meticulous management. The links are numerous and complex. Moreover, the production of cars on an assembly line may involve dozens of processes and hundreds of steps. Although there is a complete quality inspection before leaving the factory, it cannot guarantee that there will be no loopholes.

In addition, in order to ensure their own brand value, luxury brands usually focus on vehicle performance and luxury, and usually use the most advanced technology and materials. However, these new technologies may have some problems or defects in the early stage of market launch, which requires time and experience to repair and modify. In order to pursue luxury, more unnecessary designs will be added, which will further complicate the vehicle structure and may also increase the failure rate.

Why do cars leak?

Car roof leaks are mainly caused by the following reasons:

1. There is a problem with the sunroof drainage system. For example, the drainage groove is blocked by dust, fallen leaves and other debris, or the drainage pipe is cracked or deformed, resulting in rainwater not being able to drain normally, or the sunroof track is damaged, resulting in the failure to close and seal normally, which will seep into the car.

2. The sealing strips of the roof and body are aging, damaged or loose. For example, the doors and trunk doors are often opened and closed, which leads to poor sealing and water leakage when it rains.

3. The roof is broken. In particular, if the sunroof glass is hit by falling objects or is damaged by cracks, gaps, damage, corrosion or perforations due to uneven stress during assembly, it will also cause water leakage.

4. There is a problem with the installation of the luggage rack. For example, the fixing screws are not tightened, or the sealing gasket is damaged, which will cause water to flow into the car through the screw holes.

5. Product defects during vehicle design. Some models have unreasonable drainage pipe designs due to some reasons. For example, the roof water channel is located at the lowest position in the middle of the front and rear B-pillar. Although the accumulated water can be discharged by inertia during driving, if the water accumulates for a long time, it may cause the drainage pipe to be blocked or corroded and damaged, resulting in water leakage. Or there is a relatively large gap between the door and the roof of the soft-top model, which will also cause leakage when it rains.

However, in this case, there are some reports that the car owner said that the 4S shop was unable to determine the specific problem, while the 4S shop’s statement on the situation stated that the rubber and plastic parts on the upper right side of the vehicle were damaged. Currently, both parties have different opinions, so the specific cause cannot be determined.

Every vehicle is subjected to a rain test before leaving the factory. The car factory rain test is used to evaluate the waterproof and sealing performance of the car. The test simulates rain conditions of different intensities and durations, such as light rain, heavy rain, and rainstorms. The car is placed under the rain test equipment for spraying to observe whether there is water seepage inside the car and whether the watertightness of the parts meets the requirements.

Generally, water leaks, especially blockages in the drainage system, are often relatively minor seepage, and the general manifestation is water marks on the roof of the car. In this case, going to a repair shop to clean the drain can solve the problem.

A large amount of water entered the car. Image source: provided by the author

But if the problem is serious and a large amount of water has entered the car, you need to remove the soaked part of the car. At the same time, open the chassis drain to drain the water in the car, clean it and dry it. The carpet and floor mats in the car also need to be cleaned and dried. If the water is not cleaned for a long time, it will cause mold and deterioration and produce odor, and you may need to replace the carpet, floor mats or even the entire seat.

How to avoid car leaks?

The first thing is to regularly maintain your vehicle, and regularly check the door and window seals, glass seals, sunroof drainage system, and body seams. You can clean the debris left in these locations when washing the car, or ask a mechanic to help check them during normal maintenance, and deal with any problems in a timely manner.

In addition, try not to park your car in the open air for a long time, especially when it rains heavily. Drive the car into the garage, or cover the car with a car cover to prevent rainwater from flowing into the car. There is a disposable car cover on the market now. This car cover is very thin and has an elastic band at the bottom, similar to a food preservation bag. The price is very cheap and you can buy one for a few to ten yuan. It is more economical and practical.

Also, if you don't use a car for a long time, you should check it regularly. Generally, car leaks range from minor seepage to more serious leaks. Finding the fault as early as possible can reduce unnecessary losses. At the same time, running the car regularly for a period of time can also charge the battery to avoid the battery running out after a long period of non-use, which will make the car unable to start.

Planning and production

Author: Li Weiyang, a popular science author

Audit丨Feng Chao, Senior Engineer, Sany Intelligent Mining Technology Co., Ltd.

Planning丨Fu Sijia

Editor: Fu Sijia

Proofread by Xu Lai and Lin Lin