Is the pipeline connecting the throttle of Volkswagen Tiguan leaking normally?

< < strong > > Volkswagen Tiguan's throttle root pipe is leaking abnormally.

Theoretically, when the engine is working, the intake pipe is in a state of more negative pressure and less positive pressure! That is to say, most of the air is sucked into the engine due to the negative pressure formed after the engine does work. Therefore, the joint between the intake pipe and the engine will not leak oil. Even if there is oil leakage, it can't be seen by the naked eye. You must remove the pipe to check the inner wall. If you see the leaked oil from the outside, it means the air is leaking, too. If it is in front of the throttle, it is not a big problem. For example, at the back of the throttle, air leakage will lead to the change of air intake, which will lead to the unstable working state of the engine! Therefore, it is advisable to tighten the intake pipe! The possible problem still lies in the design of crankcase exhaust gas recovery system.