oil in air intake hose
 

Car is a 1990 740 sohc non-turbo 4cly. 215,000km. I pulled the air intake hose of the throttle body 6 months ago and found oil in the hose. I assume it is coming from the flame trap, so I took the flame trap out and clean it and all the hoses and cleaned the throttle. Now I took the air intake hose off again and again there is oil in the hose. The oil is being sucked in through the hose that goes to the flame trap, WHY? Is there something else I should be looking at?