What Causes the Squeaking Sound When Starting a Car?
2 Answers
The reasons for a squeaking sound when starting a car are: 1. The engine temperature is too low; 2. The three-way catalytic converter expands due to heat; 3. Transmission failure causing internal gear friction; 4. Wear of the engine belt or chain; 5. Worn hydraulic tappets or system pressure loss; 6. The clutch pedal return spring is too soft; 7. Worn, loose, damaged bearings or loose fastening nuts. Solutions for the squeaking sound when starting a car include: 1. Check for transmission faults; 2. Replace the engine belt; 3. Inspect hydraulic tappets for wear; 4. Replace the clutch pedal return spring; 5. Adjust bearings or tighten fastening nuts.
Last time my car made a squeaking noise when starting, which seems like a pretty common issue. It's usually caused by aging, loose, or dry belts, such as the alternator belt or AC belt. Due to high temperatures and wear, the surface of these belts becomes polished and loses elasticity, causing friction against the pulleys or idlers and producing a sharp noise. A cracked or loose belt, or a faulty tensioner pulley, can all lead to this. If the alternator belt squeaks and is left untreated, the charging system might fail; the AC belt affects the cooling. I've tried using lubricant spray for temporary relief, but it's best to regularly check the belt condition and replace it with a new one—just a matter of a few bucks. Otherwise, breaking down on the road would be troublesome. Insufficient lubrication is another cause, like a water pump bearing lacking oil, which produces a similar sound; the starter motor occasionally squeaks too, but that's rarer. In short, this noise is a reminder for maintenance—don't ignore it.
