What Causes a Car Engine to Make Loud Idling Noises?
2 Answers
Reasons for loud idling noises in car engines: 1. Weather conditions, especially cold weather, can cause the engine idle speed to increase. When the engine remains at high RPMs while cold, it may sound louder. This is a normal phenomenon and nothing to worry about, as almost all cars experience higher idle speeds in winter. The idle speed will decrease once the engine warms up; 2. Loose plastic components in the engine compartment, such as the engine cover or intake pipe, which can be tightened. Belt noises from components like the power steering belt or alternator belt; 3. Incorrect engine oil condition. Engine oil is crucial for lubrication, and issues with it can affect engine performance. If the oil viscosity is too high, it may cause operational problems, reduce lubrication effectiveness, and lead to increased friction and noise during engine operation.
A few days ago, my car made an unusually loud noise at idle, sounding like a tractor buzzing. It took me a while to figure it out. Typically, the most common cause for this is an issue with the exhaust system, such as a cracked exhaust pipe or a deteriorated gasket, which allows exhaust gases to leak out and increases the noise. Additionally, insufficient or degraded engine oil can increase engine friction, leading to abnormal roaring. Another possibility is improperly adjusted valve clearance or worn piston rings, where parts directly collide and produce noise. Some cars might have loose belts or bearing failures—I’ve seen similar issues with my neighbor’s car. Loud idle noise isn’t just annoying; it indicates the engine might be working under strain. If left unaddressed, fuel consumption could increase, or the car might even stall on the road. I recommend checking the exhaust and oil condition yourself first. If that doesn’t help, get it repaired early—safety comes first.
