Passat Yu Ling 1.8T engine has serious idle jitter, and the engine fault light is on.

For reference: 1, sensor damaged, poor contact or signal interruption; 2. Poor engine maintenance; 3. Poor quality of fuel and engine oil; 4. Incomplete combustion of mixed gas; 5, spark plug failure, ignition coil failure; 6, fuel pump failure, oil blockage; 7. The air conditioning filter element is blocked.

The specific situation is analyzed as follows; 1, sensor problem; The sensors mentioned here include water temperature, crankshaft position, air flow, intake air temperature, oxygen sensor, etc. When these sensors are damaged, the contact is poor or the signal is interrupted, the ECU of the automobile can't get the engine data accurately, which will lead to the engine fault light. 2. Maintenance problems; Improper engine maintenance is the most common cause of engine failure. We know that vehicles have a certain maintenance cycle. If the owner fails to maintain them on time and has bad driving habits, it will increase the burden of engine operation. Finally, you can only remind you to care about your car through the fault light. 3. Oil quality problems; The oil quality mentioned here includes fuel oil and engine oil. As we know, the full fuel of a car is generally labeled, and the engine oil is also semi-synthetic and fully synthetic. Manufacturers generally advise car owners which brand of fuel and which type of engine oil to use. If the owner does not add it as required, it will lead to long-term wear and tear of the engine, so no one will be blamed if the fault light is on. Poor combustion of mixed gas; Engine spark plug failure, ignition coil failure, fuel pump failure, oil circuit blockage, etc. Will cause poor combustion of engine mixture. The problem of engine carbon deposition or knocking caused by poor combustion of mixed gas will eventually be monitored by the engine oxygen sensor and reported to ECU, and the fault light will naturally turn on to warn the air intake problem; When the engine is burning, it needs air intake. In this process, the air filter is very important. If the air filter of a car is not clean and is not cleaned regularly, it will affect the air intake of the car. If it is blocked for a long time, it will cause the engine fault light to light up. Pressurization problem; The intake booster line and turbocharger can also cause the engine fault light to come on. One of the most common is the damage of turbocharger, at the same time, the vehicle will also leak oil, consume a lot of oil and reduce power. Personal summary for reference.