Idling is a working state of the car, which means that the engine is running in neutral. The speed at which the engine idles is called idle speed. The idle speed can be adjusted by adjusting the size of the damper. According to the automobile muffler manufacturer, idling is that the engine "can't output". When the engine is running, if the accelerator is fully released, the engine is at idle speed. When idling, the speed shall not be suddenly high and low, otherwise it will cause early wear of the engine, and it shall be adjusted by the automobile maintenance department.

1. Causes of abnormal noise in the middle section of idle exhaust

The engine is connected to the metal soft net, which is connected with the three-way catalyst, and there is a breaking sound when the soft net does not sound; The rubber lifting lug of exhaust pipe is hardened due to cold weather.

What are the causes of abnormal idle exhaust?

2. When the car is idling, it emits gunfire

The reason is that the spark is broken or weak. The manufacturer of automobile muffler suggests that the spark plug can be replaced by the user. If the combustible mixture in one stroke is not ignited, it shall be ignited with the high-temperature gas in the next stroke after being discharged and silenced. This is intermittent and irregular. The engine power decreases significantly and it is easy to shut down when accelerating. At this time, the spark plug shall be removed for fire jump test. If the spark plug is broken or weak, remove the carbon deposit or replace it with a new part.

Or the valve clearance of the impulse engine is incorrect, the valve ablation is not closed tightly, the valve phase overlap angle is too large, and the timing gear is improperly installed, resulting in the early opening of the exhaust valve, resulting in the shooting phenomenon. The ignition time of delayed combustion mixture is prolonged, and the unburned combustible mixture is combusted again in the muffler, resulting in exhaust pipe blasting. At this time, adjust the ignition advance angle time or replace the magneto.

What are the causes of abnormal idle exhaust?

3. If the idle speed is too low, adjust the idle speed to 750 rpm.

If the idle speed is normal, check the working condition of each cylinder of the engine for anal prolapse.

If the fixing screws of the exhaust pipe are loose or the silencer fails, check whether the fixing screws at all parts of the exhaust pipe are fastened and whether the weld between the automobile silencer and the exhaust pipe falls off.

What are the causes of abnormal idle exhaust?