What causes the abnormal noise when starting the car?
1 Answers
This squeaking noise is caused by belt slippage, which may be due to insufficient tension from the tensioner pulley or the belt being stretched and loose from prolonged use. Adjusting the tension should resolve this issue. Additionally, a clicking or grinding noise during the initial moment of starting the car could indicate gear engagement issues. Below is relevant information about ignition systems: Traditional Ignition: The mechanical ignition system operates by the crankshaft driving the distributor shaft, which rotates a cam to open and close the primary contacts of the ignition coil, generating high voltage. This high-voltage current is then distributed by the rotor in the distributor to each cylinder's spark plug in the required sequence, where the spark ignites the air-fuel mixture in the combustion chamber. The distributor housing can be manually rotated to adjust the basic ignition timing (idle timing), and it also includes a vacuum advance mechanism that adjusts timing based on intake manifold vacuum levels. Electronic Ignition: Electronic ignition systems differ completely from mechanical systems, incorporating an electronic control unit that contains ignition timing maps (MAP) for various engine operating conditions. Sensors such as engine speed, intake manifold vacuum (engine load), throttle position, and crankshaft position determine the engine's state and reference the MAP to find the optimal ignition timing. The system then adjusts this timing based on knock sensor feedback to ensure the engine operates at its most efficient ignition point.
