What Causes Idle Vibration in Mercedes-Benz Smart?
2 Answers
Mercedes-Benz Smart idle vibration may be caused by severe engine carbon deposits or ignition system issues. Specific problems: Severe engine carbon deposits are the most common cause of car vibration. Poor ignition system performance or bad spark plug firing conditions can also lead to such faults. Unstable oil pressure and engine aging are also likely to cause vibration in Smart. Solutions: Clean the fuel system and check if the idle motor has carbon deposits that need cleaning, then recheck after cleaning; inspect if the spark plugs have excessive carbon deposits and replace them if necessary; check the oil pressure and replace components if needed.
I've been driving a Mercedes-Benz Smart for several years, and recently encountered severe shaking at idle. This is usually caused by several common issues. The most common one is aging engine mounts, where the shock absorption function weakens, making the car prone to shaking. Another cause is severely worn spark plugs, which can lead to uneven ignition and result in shaking—this happened to my car once, and replacing them made a big difference. Additionally, if the fuel system is dirty, such as clogged fuel injectors, the engine won't get enough fuel, leading to unstable operation, especially noticeable at idle. I remember once during a check-up at the dealership, the mechanic mentioned that the three-cylinder engine design inherently has some minor issues, so a bit more vibration is normal, but if it's too frequent, repairs are needed. Carbon buildup is also a hidden culprit—too much ash in the combustion chamber or a stuck throttle can cause the engine to struggle, leading to intermittent shaking. In short, even though the shaking seems minor, don't ignore it. I recommend checking the mounts and spark plugs first, and if that doesn't help, take it to a professional shop for diagnostics—safety first.
