What causes abnormal noise when starting the car but not during normal driving?
3 Answers
The reason for abnormal noise when starting the car that disappears during normal driving is due to a malfunction in the engine compartment, where the engine's torque vibration is significant during startup. Below is relevant information about vehicle abnormal noises: Warranty coverage: Abnormal noises in the car body are covered under warranty. As long as the abnormal noise is due to issues with the car product quality, consumers can have it repaired for free by the repairer with the three-guarantee certificate. Legal provisions: According to Article 18 of the "Regulations on the Repair, Replacement, and Return of Household Automotive Products," during the warranty period of household automotive products, if there are quality problems with the product, consumers can have it repaired for free by the repairer with the three-guarantee certificate (including labor and material costs).
I've noticed many manual transmission cars make creaking or rattling noises when starting off, but the sounds disappear once reaching normal speed. This often indicates clutch issues. Specifically, the clutch disc may be worn thin, or the release bearing could be damaged. During starts when pressure is high, the struggling bearing rotation causes noise that vanishes when driving load stabilizes. Another possibility is loose clutch pressure plate causing jerky starts. Don't ignore it - prolonged neglect may lead to difficult gear shifting or clutch slippage. Best visit a repair shop for clutch system inspection. Replacing discs/bearings costs just a few hundred bucks. Other potential causes include worn engine mount rubber causing startup vibrations (silent when driving). For smooth operation, early diagnosis prevents minor issues from escalating.
My car has experienced this before - a squeaking sound when releasing the brake at startup, but it disappears while driving. I suspect it's either brake pad rust/wear causing friction noise during initial movement, or suspension components like loose ball joints making clicking sounds during gradual acceleration. I ignored it at first until the noise got louder, costing me extra repair money later. For automatic transmissions, note that transmission load during startup might cause noises, but don't hesitate to get it checked. Now during maintenance I always specifically inspect these areas to prevent potential issues. My advice: when noticing abnormal sounds, record their characteristics (metallic vs rubbery noises) to help mechanics diagnose. Safety is no trivial matter - don't ignore sounds just because they disappear when driving.
