Car Vibrates When Idle: Major Causes and More dubizzle 4 REASONS your car VIBRATES when ACCELERATING!!! Your car often gives small warnings before something fails. Next time you park, try the 5 second test. Turn off the music and let the engine idle for a moment. Hear ticking, rattling, 6 Possible Reasons Your Car is Shaking and How to Solve These Issues Matthews Tire Tire Vibration Diagnosis: Is It Safe to Keep Driving? If your car shakes at high speed the cause is often mechanical imbalance. Small issues become more noticeable as speed increases. Unbalanced tires are a common reason, creating vibration that grows