What is the problem with high shaking and vibration during cold idle?
3 Answers
Reasons for car body shaking during idle: 1. Severe engine carbon deposits: The most common cause of car shaking is dirty throttle or excessive carbon deposits in the fuel injectors. When the combustible mixture in the engine is sometimes lean and sometimes rich, it causes idle shaking after a cold start. 2. Ignition system problems: Check the working condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or spark plugs can also lead to such faults. 3. Unstable oil pressure: If you have already cleaned the engine carbon deposits, washed the throttle, and replaced the spark plugs but still notice body shaking during idle, it is recommended to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect values and poor performance of the intake pressure sensor can cause body shaking. 4. Aging engine components: Car shaking is also related to the aging of engine mounts. Engine mounts are responsible for absorbing minor vibrations during engine operation. If there is a problem with the engine mounts, these vibrations will be transmitted to the steering wheel and the cabin, causing shaking during idle.
Cold engine idle shaking and high vibration are common engine operation issues when the temperature drops. I believe this is caused by an imbalance in the air-fuel mixture combustion. Possible reasons include insufficient ignition due to aging spark plugs; clogged fuel injectors affecting gasoline spray; excessive carbon deposits inside the engine obstructing airflow; or a stuck idle control valve and dirty throttle body, which can also increase vibration. Diagnostic steps: First, check the condition of the spark plugs—remove them to inspect if the electrodes are eroded or carbon-fouled. Cleaning the throttle body can provide immediate improvement—simply spray it with a professional cleaner. Additionally, an OBD tool can be used to scan for trouble codes to confirm sensor issues. Preventive measures: Replace the air filter every 5,000 kilometers; add fuel system cleaner; and warm up the engine for 1-2 minutes after starting in winter before driving. Overall maintenance habits are key, especially for older vehicles, which are more prone to problems. It is recommended to address the issue promptly to avoid long-term vibration damage to engine bearings.
My car used to shake like dancing when starting in winter, even the steering wheel would vibrate. Later, I found out it was due to severe carbon buildup on the spark plugs, and it stabilized immediately after replacing them. Carbon deposits are one of the main culprits, especially for older cars frequently driven on short trips, which can easily get clogged. Cleaning is simple—just pour a bottle of fuel additive into the tank and drive on the highway. Clogged fuel injectors can also cause unstable idling, and you can have them cleaned at a small shop for a low cost. Dirty throttle bodies have a big impact, but you can remove the intake pipe and wipe them with spray to alleviate the issue. Faulty ignition coils are the most common problem, and replacing them costs a few hundred bucks. Remember to check the wiring connections—tightening loose ones is free. Regular maintenance, like changing spark plugs every 30,000 kilometers, can save a lot of hassle.
