06 Passat Yu Ling engine has abnormal noise, abnormal jitter and unstable idle speed.
1. The engine has serious carbon deposition.
The most common cause of automobile jitter is that the throttle valve is too dirty or the fuel injector has too much carbon deposit. When there is too much carbon deposit in the engine, the gasoline sprayed by the fuel injection head will be absorbed by a large amount of carbon deposit during cold start, which makes the cold start mixture too thin and difficult to start. In this case, it is easy to start the car only if the gasoline with carbon deposits is saturated. After the car starts, the gasoline adsorbed on the carbon deposit will be sucked into the cylinder by the vacuum suction of the engine for combustion, which will make the mixture thicker and the combustible mixture of the engine thinner and thicker, leading to cold start. The lower the temperature, the more oil is needed for cold start and the more carbon is deposited, which will affect the success of cold start.
2. Ignition system problem
Check the working conditions of spark plugs, high-voltage lines and ignition coils. If the ignition system is not good and the spark plug does not jump, it will also lead to such a failure.
3. The oil pressure is unstable
If the engine carbon deposit has been cleaned, the throttle valve has been cleaned, and the oil pad and spark plug have been replaced. And the body is still shaking when idling. I suggest you go to the 4S shop to check whether the oil supply pressure and intake pressure sensors are normal. If the oil supply pressure of the oil pump is abnormal, or the intake pressure sensor has an incorrect value and works abnormally, the body will shake.
4. Aging of engine parts
Car jitter is also related to the aging of engine feet (also known as claw pads). The engine foot is actually the damping system of the engine. The engine feet are responsible for absorbing slight vibration when the engine is running. If there is something wrong with the engine base, these vibrations will be transmitted to the steering wheel and cab, causing idle vibration.
Solutions to carbon deposition
Cleaning the oil circuit once every 5,000 kilometers can maintain the vehicle well. If the carbon deposit is not cleaned for a long time, the whole vehicle will run, the internal passage of the engine will be blocked by carbon deposit, the fuel injection in the vehicle will be blocked, and the engine power will be worse, thus reducing the power of the automobile engine, increasing fuel consumption and causing low combustion rate.