Blue Smoke from exhaust
 

I found an interesting notation while reading the BMW N63 Engine - Technical Training Workbook (Page 20)

Note: If the exhaust system produces blue smoke, it is necessary to check whether the engine is also drawing oil into the combustion chamber through the crankcase breather, which suggest that there is a fault in the area of the crankcase breather. A clear sign of a problem is an oiled up clean-air pipe.

This has been a problem with cars/engines since the 50's. If a car is smoking, the first thing to check is the crankcase vent.

Tell that to the BMW mechanics selling valve stem seals on these forums.

So you are saying that BMW V8s never need valve stem seals?

NO - I am not saying any such thing
From my short time posting - the norm on these forums had been to condemn the valve stem seals from the time anyone would mention smoke from the exhaust. These same people were claiming to replace the valve stem seals - on the weekend - at their homes - for 1/2 of what the Dealer or Independent would charge. (And maybe they were) God forbid a poster had a different opinion or suggest they diagnose each vehicle on a independent basis. Hypothetically - Can you imagine the money that could be made by a dishonest mechanic in this situation - the customer not around - maybe doing 2 "valve stem seal jobs" on a weekend.