What Causes the Sizzling Sound When Starting the Car?

[VanCooper]

The reasons for the sizzling sound when starting the car are: 1. Timing chain failure; 2. Aging of the drive belt; 3. Three-way catalytic converter failure; 4. Engine temperature too low; 5. Engine belt slippage; 6. Severe wear of the starter and flywheel; 7. Valve train failure; 8. Excessive gap between the hydraulic system and valves inside the engine cylinder head. The steps to start the car are: 1. Insert the key into the ignition switch, turn it up one notch to activate the fuel pump for oil supply and initiate self-check of electrical equipment; 2. Press the clutch and turn the key further up to start the vehicle; 3. Press the clutch, shift gears, and release the handbrake.

[SanCali]

After driving for so many years, the buzzing sound during startup is really annoying. It's mostly due to worn gears in the starter motor, which make noise during friction, especially noticeable during cold starts. It could also be a loose or dried-out alternator belt slipping and squeaking. I experienced this once—the noise kept getting louder, and later inspection revealed a failed water pump bearing. Replacing the entire unit finally brought silence. I recommend carefully listening to the sound location after starting: if it's near the front compartment, focus on the belt; if it's closer to the rear, the starter motor is the likely culprit. If it gets severe, the belt might snap, leading to startup failure and requiring a tow, which is time-consuming and costly. During regular maintenance, I always ask the technician to check the belt tension and starter motor condition—prevention is much better than emergency repairs.

[PeytonMarie]

My car repair experience tells me that a buzzing sound during startup is quite common, usually caused by a few reasons: worn starter motor gears causing grinding noise, loose alternator belt creating squeaky friction, or bearing issues within the alternator itself. When diagnosing, first locate the sound source - front area often indicates belt problems, while rear suggests starter motor issues. Cracked aging belts or insufficient lubrication of the motor can worsen the problem, and delayed repairs may lead to starting difficulties or driving interruptions. I've handled many similar cases where early intervention costs less. Recommended maintenance: check belt tension and wear every six months, adjust or replace if necessary. For those with DIY skills, you can gently press the belt to test tension, but it's best to visit a professional shop to ensure safety.

[LaDamian]

The buzzing sound when starting the car has me a bit worried. Last time my car did this, my mechanic friend said it was likely due to the starter motor gear not being tight enough or friction noise from a slipping belt. An old, loose belt can squeal during startup, and if it gets worse, the belt might snap, leaving the car unable to move. As an ordinary person, I didn’t dare to mess with it and went straight to a nearby repair shop for a checkup—turned out to be a minor issue fixed easily. I suggest you note the duration and location of the sound and jot it down in your phone for the technician’s reference. Don’t delay; addressing it early is safer and more reliable, avoiding the embarrassment of a roadside breakdown. Adding some lubrication during maintenance can also extend the lifespan of the components.