1. Serpentine belt: The serpentine belt is a long, thin belt that runs around the front of the engine and connects various components, such as the alternator, power steering pump, and air conditioner compressor. If the serpentine belt is loose or damaged, it can make a screeching noise when the engine is started.
2. Alternator: The alternator is a device that generates electricity for the car's battery and various electrical components. If the alternator is faulty, it can make a screeching noise when the engine is started.
3. Power steering pump: The power steering pump is a device that provides hydraulic pressure for the car's power steering system. If the power steering pump is faulty, it can make a screeching noise when the engine is started.
4. Water pump: The water pump is a device that circulates coolant throughout the engine to keep it cool. If the water pump is faulty, it can make a screeching noise when the engine is started.
If you are hearing a screeching noise when you start your 2001 BMW 740i, it is important to have it checked out by a qualified mechanic as soon as possible to identify and address the problem.
