Hello

I'm looking for information on the topic: oil catch tank.

First of all I'm trying to understand if the oil vapor collection system in the 20v turbo is efficient or not, what I can say is that the vapors still loaded with oil end up in the intake duct, dirtying the internal surfaces.

Here, many discussions about this have lead me to a dead end though, what kind of catch tank to buy?
with ho without built-in filter?
how to attach to already existing lines?
completely bypass the old tank or add a new catch tank to the old one?

The idea would be to eliminate the old and add the new with an external filter so that no vapor enters the circuit, but I don't have the answer to understand if the vapors will be pushed from the crankcase without a vacuum from the induction tube ?

All the advice and the experience you have can be useful to understand how best to do it.
purchase links are also welcome.

I have a picture of the original tank schematic.

In my opinion, there is no need for an additional aftermarket catch tank. If you are finding that your intake lines are loaded with oil, I would check that the 1-way valve (Number 7 in the diagram) is functioning properly.

Disconnect it from the plenum and try blowing through it. If you can blow through it with minimal effort, it means the valve is no longer working and any positive pressure from the plenum will result in oil being blown out of the catch tank and fouling your intake with oil.

If the valve is functioning properly, it will help draw out out oil vapors from the cam cover when the plenum is under negative pressure (vacuum). Condensed oil vapors are then fed back to the sump.

Thanks

I would think the PCV is good on the coupe . My Friend who has a BMWE92 325I has PCV problems for years and they are well known for this . We took his inlet manifold off about 3 months ago and the bottom of it was full of oil . Every time he accelerates hard there is a cloud of smoke Batman would be proud of . So we changed the cam cover from plastic to metal as they leak and after about 2 weeks the oil problem came back The PCV is built into the cam cover . I suggested an oil catch tank and he bought one off Ebay for about £25 pounds . It works great and every couple of 100s miles he has to drain the oil catch tank . No more smoke out the exhaust . Within fitting it a friend brought a BMW E60 V8 with a a smokey engine . He changed his PCV valve but the problem persisted . I told him to pull the bonnet and right in the corner was a aftermarket oil catch tank . We opened it and it was full . So he emptied it and has been fine since . BMWs suffer from this problem . So to sum up i have had good results with oil catch tanks