There are two basic reasons for loud engine noise: excessive carbon deposits in the engine. The engine oil is unsuitable or the oil is dirty.
In addition, most of the motor noise is caused by abnormal motor noise:
1. Screw of the lower motor protection board are loose. A relatively common minor fault is the tightening or adjustment of the lower engine skid plate screws.
2. The motor dog shoes are getting old. The claw pads play a role in supporting the engine and can only be replaced after aging.
3. Plastic parts in the engine compartment are loose. For example, engine cover, air intake pipe, etc. can be tightened.
4. The motor belt makes an abnormal noise. Including power belts, generator belts, etc. If the belt is old or tooloose or too tight, it will produce abnormal noise. Replace or adjust the seal.
5. Engine knocking. There are too many carbon deposits inside the engine or fuel consumption is substandard. Clean carbon deposits and replace fuel.
6. Abnormal valve noise. Especially once the car is cold, the valve will make a "click-click" sound, then everything will be fine when the car is warmed up. This is because the engine oil settles in the oil pan and is not “squeezed”. when the engine starts. But if the valve continues to ring, you should consider switching to a thicker engine oil (for how to choose engine oil, please refer to "How to choose engine oil correctly").
7. Engine “backfire” failure. The engine will make a "puffing" noise, which may be caused by excessive carbon deposits on the valves orincorrect timing adjustment. Clean carbon deposits from the valves and adjust the valve timing.
8. The engine is missing a cylinder. If a certain cylinder does not ignite, it is most likely that the spark plug or ignition module is defective and can be replaced.
9. Abnormal noise from the bearing. There will regularly be "hums" in bearings, such as motor tensioners, rollers, generators, etc. This problem can be resolved by replacing the affected parts.