Car Vibrates When Idle: Major Causes and More dubizzle Engine shaking while idling? That small vibration is usually worn engine mountsand it only gets worse with time. Left too long, it can lead to extra strain on your engine, gearbox, and even your Customer states: small vibration., Meanwhile the engine mount: , If your car shakes while idling, clunks when shifting, or feels rough while driving, your engine mounts could be failing., Bad Why does my engine vibrate at idle only when I have the AC on? Motor Vehicle Maintenance & Repair Stack Exchange Why Does My Car Shake at Idle but Smooth Out While Driving? 2008 Honda Civic Vibration during Idle and Deceleration 8th Generation Honda Civic Forum