There is no flame trap on the turbos. The breather box can get clogged up though. With the engine running, cold, remove the filler cap and place your hand over the opening. You should feel a suction, like a vac cleaner but not as strong. Then wipe the oil off your hands.

Some folks dump a little oil down the hose going into the breather box and watch it run out oil drain to help clean it and to verify that it is not clogged.

If you have the smaller breather box and no EGR blocking it you can remove and replace or clean it. There is a good FAQ info on that if your up to it. I have the giant breather box with an EGR valve in the way. I'd have to remove the intake manifold on my T to get it out.
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Tom F