Radio89

Hi all,

I've noticed that my crank case breather sucks up oil from the crank case and deposits the oil in the intake plenum over the course of a few weeks. This happens regardless of high/low oil level or distance travelled ie. frequent short trips or frequent long trips. Is this a normal occurrence for this type of vehicle? When changing the spark plugs, #4 which is the closest to the breather was very heavily deposited with ash, presumably as this cylinder is burning the oil from the crank case the most. All cylinders were noticeably carbonated, again most likely from the crank case oil. The intake valves were also noticeably carbonated. If I don't clean the oil residue regularly it can go as far as to contaminate my throttle body, MAF sensor and stain my intake filter. Have others on the forum noticed this or is it a case that there is a seal missing in the breather or on the primary flexible intake tube? Otherwise I'm thinking to create some kind of replaceable, breathable filter to capture the oil which can be safely inserted into the breather hose to prevent this issue from continuing and replace monthly or as needed.

From what I can see Audi use a negative crank case pressure system for this vehicle series whereby the engine vacuum creates negative pressure in the crank case at all times so no positive pressure can develop (the downside being oil siphoning), as opposed to a PCV valve system whereby only positive pressure is vented.

I would be interested to hear form those who have the same engine type or have experienced this phenomenon.

Audi A3 8L1 BFQ 8v 1.6L Petrol 75KW 102HP 5 Door