The engine of Audi A6L wobbled at idle speed, and the mechanic checked it all day.

Unexpectedly, the fault code shows that there is something wrong with the throttle, indicating that there is something wrong with the throttle opening and it needs to be cleaned. After the owner agreed to clean, the mechanic removed the throttle, as shown below! There is a large amount of carbon deposit on the edge of the throttle valve, which will lead to air intake problems. This is the front of the throttle, not obvious!

As shown in the figure below, this is the back of the throttle valve, which is the side installed above the intake manifold. We can see that the carbon deposition here is particularly obvious! This will also cause the throttle to jam, leading to the problem of unstable engine idle speed!

The cleaning of the throttle is particularly simple! The mechanic cleaned the throttle quickly, as shown by the orange arrow in the figure below. Then the mechanic needs to install the throttle!

After installing the throttle, the mechanic asked the owner if he had changed the spark plug, but he didn't expect the owner to change the spark plug yet! You know, turbocharged engines require a spark plug replacement cycle of 20,000 kilometers, and now it is more than 40,000 kilometers. It is time to change! So, the auto mechanic removed the spark plug, as shown in the red area below!

Seeing the spark plug in the above picture, the mechanic suggested the owner to replace it with a new one, and the owner agreed to replace it! As shown by the green arrow below, this is a new spark plug!

After the auto mechanic changed the spark plug, it is suggested that the owner add a bottle of fuel additive, which will help improve the oil circuit and nozzle! As shown below, the mechanic is adding fuel additives!

After the mechanic finishes these tasks, he unscrews the key and connects the computer to match the throttle! Then start the engine, and the idle speed is normal! The owner is quite satisfied with the maintenance results! Finally, the owner has doubts, how can there be so much carbon deposit on the throttle? How to avoid it?

According to the master, part of the carbon deposit on the throttle comes from impurities in the outside air, and the other part comes from the oil vapor inside the engine! Basically, all types of car throttles will have carbon deposits, which is inevitable. Under normal circumstances, it's easy to clean the throttle for 20,000 kilometers! Spark plugs also need to be replaced in time!