What Causes the Buzzing Noise When Accelerating Hard in a Roewe 350?
2 Answers
Roewe 350 experiencing abnormal noise when accelerating hard is related to engine speed. Most common engine abnormal noises depend on the engine's speed state. The specific causes of abnormal noises under the following three conditions—idle or low-speed operation, maintaining a certain speed, and sudden engine acceleration—are as follows: Occurring during idle or low-speed operation: The cause of the noise may be excessive clearance between the piston and cylinder wall; overly tight piston pin or connecting rod bearing assembly; excessive clearance between the tappet and its guide hole; wear on the camshaft profile; sometimes, a loose starter clutch causing pulley noise (more noticeable during speed changes). Sound disorder when maintaining a certain speed: Successive short noises occur during rapid deceleration. The cause may be a cracked camshaft timing gear or loose fixing nut; broken crankshaft; loose piston pin bushing; excessive camshaft axial clearance or loose bushing. Abnormal noise during sudden engine acceleration: The noise persists when maintaining high-speed operation. The cause may be loose connecting rod bearings, melted or mismatched bearing shells causing rotation; loose crankshaft bearings or melted bearing shells; broken piston pin; broken crankshaft.
I also experienced the issue of a buzzing noise when flooring the accelerator in my Roewe 350, which was quite annoying. I think there might be two main reasons: one is that some parts in the engine compartment are loose or faulty, such as a dirty air filter or an air leak in the intake system, amplifying the airflow noise; the other could be a gap in the exhaust pipe, causing noise from airflow impact at high speeds. It might also be due to vibrations from an aging fan or belt. I remember that time the buzzing was accompanied by slight shaking, so I quickly checked the engine oil and coolant, finding the oil level a bit low. After topping it up, the noise improved slightly. However, it's best not to delay—buzzing when flooring the accelerator could pose safety risks, and engine damage would be troublesome. I recommend visiting a repair shop to have a mechanic identify the noise source. Usually, replacing the filter or reinforcing the exhaust pipe can solve the problem. Regular maintenance of these wear-prone parts can help prevent similar issues.
