Aporte original por: Pete ,
There is some missing information. You don't say what year your car is or if it is a turbodiesel. If it is a California car there are further differences in the air filter arrangement. Assuming the most common configuration, remove your air filter housing and you will find a short steel tube extending from the bottom of the housing. That tube should have an o-ring on it. If it has none or the o-ring is old and hardened, replace it. That tube then fits into another steel tube extending up from the engine block to provide a drain-back path from the air filter housing to the crankcase for excess oil. It is easy to miss the mating of those two tubes when replacing the lower half of your air filter housing. It is a blind fit you will have to feel with your fingers while seating the housing.