What caused the engine exhaust pipe to burn red?

1. Lack of cylinder. Some cylinders do not work, resulting in unburned gasoline in the cylinders entering the exhaust pipe for combustion.

2. The valve timing and ignition timing are incorrect. At the same time, the incompletely burned gasoline will enter the exhaust pipe and continue to burn, resulting in unstable idle speed, difficult start-up and insufficient power.

3. The fuel injector is over-injected, so it is necessary to replace the fuel injector, turbocharger and valve.

4. When the car is driving at a high speed with high load for a long time, or when the slope is large and long, the throttle is always in a fully open or nearly fully open position, the exhaust temperature is high, and the gear is only in the first or second gear, so the speed is low, the wind resistance is small, and the cooling is poor.

5. The exhaust valve clearance is too large, which leads to the exhaust valve opening too late.

6. The valve spring is too soft, which leads to the late opening and closing of the exhaust valve, which not only makes the intake branch pipe "explode", but also affects the temperature of the exhaust pipe.

7. The ignition time is too late. When the exhaust valve is opened, some stick gas is burning, so the exhaust pipe temperature is very high.

8. There is too much carbon in the exhaust pipe and muffler to transfer heat, which leads to the exhaust pipe burning red.