What Causes Car Shaking at 30-40 MPH?
1 Answers
Reasons for car shaking at 30-40 MPH: 1. Possible wheel imbalance issues or resonance-induced vibration, recommend owners to visit a 4S shop for inspection; 2. Severe engine carbon buildup causing dirty throttle or injector deposits, incomplete fuel combustion in the chamber affecting power transmission; 3. Tire deformation due to daily wear, collisions or aging; 4. Fuel system malfunction with unstable oil pressure leading to inconsistent air-fuel mixture concentration, causing both shaking and unstable idling; 5. Misfiring cylinders - a common engine shaking cause originating from faulty ignition coils or spark plugs failing to fire properly.