The engine has a rattling sound, and the engine rattles regularly
The engine makes a rattling sound, and the engine rattles regularly. Is this normal? Many car owners are extremely sensitive to abnormal noise in the engine compartment, and feel that there is a problem with their engine after a little disturbance, not to mention the regular rattle. Here we distinguish between the two situations of engine rattling.
Normal clatter
1. Disadvantages of in-cylinder direct injection technology
In-cylinder direct-injection engines tend to have relatively loud noise, because this in-cylinder direct-injection engine has a fuel injection pressure that is ten times that of ordinary engines. Then the fuel injector will vibrate during high-pressure injection. Or, when driving slowly, it is especially easy to hear the rattle.
2. The canister solenoid valve works
The function of the canister solenoid valve is that when the engine is started, the solenoid valve installed between the canister and the intake manifold is opened, and the gasoline vapor adsorbed in the canister is brought into the cylinder along with air to participate in combustion. This not only reduces emissions, but also reduces fuel consumption. This part will also have a crisp rattling sound during the working process.
3. Car cold start
Many car owners will hear a "da da" abnormal noise in the engine compartment during a cold start of the car. In fact, this "da da" abnormal noise is due to the fact that the oil pump has not yet fully established the oil pressure during the cold start, resulting in the failure of various components. Lack of lubrication. Under normal circumstances, when the engine has been running for a period of time, the clattering noise will disappear.
Abnormal clatter
1. The machine foot glue is aging or loose
Engine foot glue is the rubber block between the engine and the frame. Its function is to reduce the vibration and cushioning of the engine when it is working, and it has the effect of fixing the engine. Once these engine mounts are aging or loose, the engine will shake, and in severe cases, there will be a "da da" abnormal noise. This only needs to be replaced with a new engine mount.
2. The mixture is too thick
When the engine mixture is too rich, the symptoms are: acceleration is difficult after starting, and the engine runs unevenly; the exhaust pipe emits black smoke, the engine is accompanied by abnormal noises, and sometimes the gun is fired; the engine power decreases and fuel consumption increases. Most of this is related to carbon deposits, filter clogging, etc., and there is generally no need for major repairs.
3. Abnormal sound of "knocking cylinder"
Due to poor lubrication conditions, the piston and cylinder wall are excessively worn, causing the clearance fit tolerance between the piston and the cylinder wall to exceed the normal range. When the engine is running, the piston skirt collides with the cylinder wall and produces a “da da da” crisp sound, generally at idle speed Or it is more obvious when running at low speed.