Why is the new car's engine shaking?
2 Answers
Here are the reasons for engine shaking: 1. Aging or loosening of engine mounts. Engine mounts are rubber blocks placed between the engine and the frame, designed to reduce vibrations and shocks during engine operation and to secure the engine. Once these mounts age or become loose, the engine's shaking will become noticeably abnormal. 2. Engine misfire. An engine misfire occurs when one or more cylinders are not functioning properly, typically manifested as intermittent exhaust gas flow from the car. The exhaust pipe shakes violently, and the engine's shaking is clearly noticeable. Sometimes, this is accompanied by a sputtering sound, often related to ignition coil failure. 3. Engine carbon buildup issues. Carbon buildup includes deposits in the cylinders, throttle body, spark plugs, and intake system—all critical areas affecting the engine's power output. Excessive carbon buildup inside the engine reduces ignition energy and intake efficiency, ultimately leading to symptoms like engine shaking and sluggish acceleration. 4. Fuel system malfunction. Using an incompatible fuel grade (e.g., filling 93-grade fuel with 90-grade) can reduce the car's power output and performance. Alternatively, blockages in the fuel tank vent, fuel tank switch, fuel filter, or the fuel line between the tank and the carburetor can restrict fuel supply, resulting in a lean air-fuel mixture and engine shaking.
It's really annoying when a brand-new car starts shaking! I've encountered quite a few similar cases, and the most common issue is related to fuel. Some car owners try to save money by filling up with 92-octane gasoline from small gas stations, resulting in engine knocking that makes the car shake like a massage chair. Another issue is improperly installed engine mounts—misaligned rubber damping blocks or loose screws can cause the steering wheel to dance at idle. Carbon buildup is also not to be underestimated; if a new car is constantly stuck in city traffic during the break-in period, the throttle body can get dirty quickly. The worst-case scenario is a batch problem with ignition coils or spark plugs—this requires an immediate trip to the dealership to check the trouble codes. Oh, and a loose fuel cap causing fuel vapor leakage can also trigger shaking.
