Why is the engine noise loud when the car just starts?
3 Answers
Car just starts the engine noise loud reason is the aging of the engine mounts, the vehicle noise will become larger during cold starts. Below is the relevant introduction: Aging of engine mounts: The aging of engine mounts leads to the inability to reduce vibrations. The engine and the frame are connected in a flexible manner. There are engine mounts between the engine and the frame, and over time, the rubber bushings of the mounts gradually age and lose their original shock absorption effect, so the noise naturally becomes louder. Vehicle noise becomes louder during cold starts: During cold starts when the temperature is low, the vehicle's idle speed will be higher, and the shaking situation will intensify. However, as long as the vehicle temperature rises, the noise will significantly decrease.
Every morning when I start my car, I encounter this situation - the engine sounds really loud right after ignition. This is mainly because during a cold start, the engine oil hasn't fully circulated to all components yet, causing dry metal-to-metal friction that generates significant noise. My car is turbocharged, and in winter the startup RPM can reach as high as 1500. After waiting about a minute, the tachometer needle drops to 800 RPM and it becomes quiet. If the weather is humid or the car hasn't been driven for a while, accumulated condensation in the exhaust pipe might make popping sounds when blown out. Actually, as long as the noise disappears after the engine warms up, there's no need to worry. But if unusual sounds persist, it might be necessary to check the engine oil viscosity and oil pump condition.
As a long-time car owner, I actually feel reassured when I hear the engine rumbling upon startup. It's designed that way—the temperature sensor detects the engine is cold and intentionally increases the RPM to help the catalytic converter reach operating temperature faster. Many friends complain about this issue in winter, but higher-than-idle RPM is completely normal. However, it's important to distinguish healthy noises from abnormal ones: squeaky belts may indicate a worn tensioner, metallic knocking could mean excessive carbon buildup, and ticking sounds often point to insufficient oil in the hydraulic lifters. Just let the car warm up for 30 seconds before driving in the morning. Frequent short trips actually promote carbon deposits that impair heat dissipation.
