What Causes the Abnormal Noise During Cold Start of an Audi?
2 Answers
Audi cold start abnormal noise is mainly caused by the following reasons: Lack of lubrication in the starter internal gears: The abnormal noise during cold start is generally due to the lack of lubrication in the starter internal gears, leading to stiffness or jamming, which affects the timely return of the gears. That is, when starting the engine, the starter rotates to drive the flywheel, thereby starting the engine. At this time, the engine speed is driven by the starter, so the engine speed is lower than the starter speed. When the engine speed exceeds the starter speed after starting, the ignition switch is manually turned off, and the starter stops. Excessive dirt inside the starter: Due to excessive dirt inside the starter and the failure of lubricating oil, the flywheel engine forcibly drives the starter to operate at its own speed. Because there is a speed difference between the two, this causes the starter to produce abnormal noise.
I've encountered many Audi owners complaining about clicking or squeaking noises during cold starts. This is usually related to the engine timing system, particularly when the timing chain tensioner lacks sufficient oil pressure in cold conditions, failing to properly tension the chain and causing it to slap against the guides. Other causes include aging or loose belts, delayed oil pump delivery, or worn water pump bearings—these components are prone to making noise when lubrication is inadequate in low temperatures. Long-term neglect may lead to chain elongation affecting timing, or even skipped teeth damaging the engine. It's recommended to first check the oil level and viscosity, ensuring the use of full synthetic oil, and perform regular maintenance to prevent issues. It's best to visit a professional repair shop for diagnosis as soon as possible—safe driving is more important than anything else.
