body frame
First of all, the frame structure of the car body is the most important evaluation basis for a used car. The frame of the car body mainly includes three parts: front beam, middle longitudinal beam and rear beam. At rest, we can generally observe the front cross beam of the car body with the naked eye. For cars, it is located at the back of the water tank (except for vehicles with rear engine), and its main function is to support the weight of the engine and absorb (or resist) the impact force during frontal collision, in which the front bumper is installed. If it is observed that the front cross beam of the car body has been deformed, bent or folded, it means that the front of the car has had a serious collision, which is likely to affect the engine part, so the car buyer will bring serious safety hazards in the daily use process.
For the longitudinal beam of the car body, it is the middle part of the car body, and the main parts of the car such as seat, floor and shell are installed on the left and right longitudinal beams. You can lift the car body properly and observe whether the longitudinal beam has any traces of dressing. If one side of the longitudinal beam is bent and deformed, it means that this side of the car body has been severely hit, and the door frame connected with it must have been trimmed. At the same time, because the longitudinal beam, the front beam and the rear beam constitute the most basic frame of the car body, when the longitudinal beam changes, the driving state of the vehicle will seriously deviate from the requirements of safe driving.
Whether it is a car, a hatchback, an MPV or an SUV, the rear beam of the car body is the key component to bear the impact from the tail and carry the weight of luggage. For the rear beam of the car body, some models can be directly observed with the naked eye after lifting the car body, while others cannot be directly seen. Then for the latter case, it can be judged by the floor flatness of the trunk or storage box. Generally speaking, if the floor surface is uneven, it means that the rear of the car is basically intact and there has been no serious rear-end collision.
Body parts
On the premise that the body frame is not deformed, bent or twisted, the next step is to observe whether the relative connections between the parts of the body are tight and whether the gaps are uniform. It mainly includes whether the position of the hood is offset relative to the left and right fenders at the front end, and whether there is a relative height dislocation; Whether the gap between the door edge and the door frame is moderate, whether the door and the adjacent parts are on the same plane, and whether it is too smooth. The connection position between the door and the door frame is symmetrical, and the door does not contact with the surrounding parts when opening and closing. If the above phenomenon does not appear, it can be judged that the external structure of the car body has no collision, or it can meet the daily safety use after repair.
Roller body surface
During the daily use or parking of vehicles, the paint surface will inevitably be damaged by foreign objects. For the resulting paint defects, it is suggested that car buyers should treat them differently when choosing vehicles.
The first performance is that there are many pits on the paint surface, about the size of rice grains, many of which are located in the front bumper and hood. This phenomenon is mostly caused by high-speed driving, so for a used car, it will not affect the normal use of the vehicle, but will make some discounts on aesthetics.
Secondly, the paint color of the car body is inconsistent with that of the adjacent car paint. On the one hand, this phenomenon is due to scratches there, on the other hand, it may be due to slight scratches and color difference caused by repainting. Neither of these conditions will affect the normal use of the vehicle.
Thirdly, the orange peel phenomenon of the car paint on the first part of the car body surface or its luster is obviously inconsistent with other adjacent surfaces, which indicates that the technical level of workers is not up to standard in the process of painting, which may shorten the anti-corrosion and anti-rust ability of the paint surface and affect the overall beauty of the car body. It is suggested that due attention should be paid to this when choosing a car.
Fourth, the body is completely repainted. This phenomenon mostly occurs in vehicles that have been used for a long time. Generally speaking, as long as the surface of the car body is sprayed evenly, there will not be too much residual paint on each sealing strip, but this will not affect the overall evaluation of the car and prolong the effective life of the car paint.