^ that's the key right there. The drains and the oil at the seals are not anywhere near the same pressure as within the pressurized side of the oiling system due to the size of the lines feeding the turbo versus the volume they drain into.

 

So you are saying at idle and decel there *may* be enough pressure in the crankcase to cause a perfectly good seal in a relatively new turbo to leak ? I have doubts and still do, peter never convinced me of this and I still have doubts.

If the seals are bad, they leak - even on a brand new turbo, that is my point. The memo is trying to explain why basically a new turbo seal may leak due to high crankcase pressure either at idle or slight decel. If the crankcase pressure is that high then surely you can measure it by simply placing your hand over the oil filler tube, lol. Gravity has to drain the turbo and under 'normal' circumstances the crankcase pressure at idle is in vacuum ( and decel ).

I just don't get it - still no worries, I am no expert

 

My car would smoke when idling, especially in the winter. But during the hot summers, i can idle without smoking. With all things being equal, Im still wondering, how come? Can anyone shed some light on this?

 

that's water vapor