Changan Xingguang 6390SC hot car is difficult to start.

The first is the difficulty of hot start: the ignition intensity of the high-voltage ignition coil weakens after the temperature of the ignition coil rises, which makes it difficult to start, or it may be that the fuel injection amount is too large, which leads to the rich mixture.

Secondly, about the abnormal noise of the engine: it is definitely not a rod noise. They may say that the knocking of the valve or air valve is due to early ignition time or high temperature. There are several main reasons: the gasoline label can't match the ignition advance time, the engine temperature is too high (water temperature), and there is too much carbon in the combustion chamber, so it is not maintained on time.

I wonder if the compression ratio (cylinder pressure) of your car is up to standard. Check the air intake system under normal oil supply and power supply, check whether the air inlet pipe of the air filter is blocked, and check whether the cylinder pressure meets the factory normal standard, otherwise the valve piston ring is not tightly sealed.

You'd better find an expert to see, ordinary maintenance apprentices can't cope.

What is said on the first floor is superficial and interesting, and what is said on the second floor is completely confusing.