Why is the car engine noise loud?
2 Answers
There are several specific reasons for increased engine noise: 1. Engine mount aging or loosening - Engine mounts are rubber blocks between the engine and frame. Solution: Tighten or replace engine mounts. 2. Improper oil usage - When oil viscosity doesn't match the engine, it can easily cause carbon buildup, leading to louder engine noise. Solution: Use the oil grade specified in the vehicle manual and avoid mixing different oil brands. 3. Engine misfire - This refers to one or more cylinders not functioning properly. Solution: Check each ignition coil and cylinder spark plug operation individually.
A couple of days ago, the engine of my old car started making a rumbling noise. I took it to the repair shop where Old Zhang checked it and listed seven or eight possible causes on his fingers. The most common issue is when the engine oil ages and thins, reducing its lubrication effectiveness, causing parts to grind and make noise. Another possibility is an air leak in the intake system—when rubber tubes crack, the hissing sound from the leak is quite noticeable. If the exhaust pipe has a hole, the popping noise can sound like a tractor. Old Zhang mentioned that a loose or slipping belt can produce a squeaking sound, and worn engine mounts can cause the entire engine to shake and rattle. The most troublesome issue is excessive carbon buildup, which creates a knocking sound like hitting a metal drum. I remember when he inspected my car, he used a stethoscope-like tool to check around and eventually found that the exhaust manifold gasket had burned through. The mechanic explained that these abnormal noises can be high-frequency or low-frequency, and the approach to fixing metallic grinding sounds differs completely from handling dull rumbling noises.
