What causes the car to shake between 30-40 mph but disappear after acceleration?

[Max]

The reasons for car shaking between 30-40 mph that disappears after acceleration are as follows: Severe engine carbon buildup: The most common cause of car shaking is a dirty throttle body or excessive carbon deposits in the fuel injectors. Solution: Clean the fuel system and check if the idle speed motor has carbon buildup that needs cleaning. It's recommended to use BOD's 'Fuel System Cleaner' - simply add it to the fuel tank during refueling to achieve fuel system cleaning effects. Ignition system issues: Check the working condition of spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or bad spark plug firing can also cause this type of fault. Solution: Check if spark plugs have excessive carbon buildup and replace them if necessary. Unstable fuel pressure: It's recommended to visit a 4S shop to check fuel supply pressure and intake pressure sensors. Abnormal fuel pump pressure or incorrect readings/malfunction of intake pressure sensors can cause vehicle shaking. Solution: Check fuel pressure and replace components if necessary.