Is it normal for 20 10 lexus es 240 Deluxe Edition engine compartment screws to rust?

20 10 the engine compartment of lexus es 240 deluxe edition is rusted. Is it normal? The idle motor of the car is above the accelerator cooker. It is mainly used to bear the idle speed of the car, and its purpose is to adjust the idle speed according to the engine load at idle speed. Idle jitter can check the pointer fluctuation of idle meter, which is generally manifested as poor combustion. If it is a new car, the idle parts will not be damaged, because the combustion requirements of the turbo direct injection vehicle are very difficult, so it is better to clean the oil circuit first. Before the idle pointer fluctuated, after the company's general fuel additive was added to the fuel tank, two boxes of oil were shaken at idle speed.