What Causes Engine Vibration at Idle?
2 Answers
Causes of idle vibration include severe engine carbon deposits, ignition system issues, unstable oil pressure, and aging engine components. Body vibration at idle is a symptom of internal vehicle problems and should not be ignored, as it may indicate serious underlying issues. Here are additional details: 1. Engine carbon deposits: A very common cause of car vibration is a dirty throttle body or excessive carbon buildup in the fuel injectors. Solution: Clean the fuel system and check the idle control valve for carbon deposits. 2. Ignition system problems: Check the condition of spark plugs, high-voltage wires, and ignition coils. Poor ignition system performance or weak spark plug firing can also cause this type of fault. Solution: Check if spark plugs have excessive carbon buildup and replace them if necessary.
My car used to vibrate heavily at idle, and after checking, I found out it was due to engine mounts. Those rubber mounts lose their cushioning effect when they age, causing engine vibrations to transmit directly into the car. Additionally, damaged ignition coils can make the engine run unevenly, and not replacing spark plugs on time is a common issue—uneven ignition leads to more vibration. Clogged or dirty fuel injectors can also cause unstable fuel supply, and excessive carbon buildup in the throttle body often causes trouble. At idle, the engine runs at its lowest RPM, making these minor issues more noticeable and vibrations more pronounced. Ignoring these problems long-term not only makes driving uncomfortable but can also increase fuel consumption or accelerate component wear. I suggest first checking the spark plugs and air filter as a simple start. If that doesn’t help, it’s best to visit a repair shop for a professional diagnosis—don’t wait until the problem gets worse.
