What is the impact of engine knocking in the ix35 on the vehicle?

[MaliaMarie]

Engine knocking, also known as detonation, can slightly increase engine power when it is mild. However, when severe, it can lead to a decrease in power and speed, unstable operation, severe engine shaking, and cause the engine to overheat and emit black smoke. Solutions for engine knocking: When the engine knocks, use a screwdriver to ground the spark plug and listen one by one to identify the cylinder producing the noise. Alternatively, inject a small amount of oil into the cylinder, install the spark plug, and start the engine. If the noise weakens or disappears and then reappears after a while, it can be determined as cylinder knocking. If the engine operates at normal temperature but the cylinder still exhibits significant knocking, the cause should be promptly identified and resolved. For diesel engines, fix the speed at the position where knocking is loudest and use the method of cutting off fuel to each cylinder for testing. Disconnect the high-pressure oil pipe of the cylinder. If the sound significantly weakens or disappears during the test, it indicates that the piston is knocking against the cylinder wall. At idle speed, the abnormal sound of the piston knocking against the cylinder is particularly clear. As the diesel engine's water temperature rises or the speed exceeds medium speed, the noise reduces or disappears. Remove the injector, inject a small amount of oil into the cylinder from its installation hole, and use the starter to rotate the diesel engine's crankshaft several times to fill the gap between the piston and cylinder wall with lubricating oil film, then start the diesel engine. If the sound significantly weakens or disappears immediately after starting, but quickly reappears as the oil film is lost or burned off, it indicates abnormal knocking in the cylinder. Remove the piston connecting rod assembly and use an outside micrometer and cylinder gauge to measure whether the fit clearance between the piston and cylinder, and between the piston pin and piston pin hole meets usage requirements. The mechanism of detonation is complex. Simply put, during normal combustion, the flame should start from the ignition center (spark plug) and spread to the entire combustion chamber at a speed of 30-70 m/s. Detonation occurs when, due to certain reasons (such as carbon deposits or low fuel grade), multiple points in the cylinder ignite simultaneously before the flame arrives, causing a sharp increase in local pressure and temperature. The pressure wave oscillates at high frequency in the cylinder, and the flame propagation speed can reach up to 1000 m/s during severe detonation.