Hi I have a 2008 550i and I am going to keep this short as possible.

I noticed white/blueish smoke coming from the tailpipe this morning, didnt think of it too much, its a BMW and a v8 lol. The valve stem seals were replaced at 89k miles (I just hit 140k) so I feel like it wouldnt be that. I do have a small oil leak, not sure where its coming from, possibly valve cover gasket or rear main seal. I checked the PCV valve and it was perfect, so any help would be great.

 

It could be you’re adding too much oil and the catalytic converters and exhaust pipes are burning that away slowly. Otherwise it can just be age and not a concern. Re-ringing the pistons is too expensive and head gaskets wouldn’t really be too likely to get oil in a cylinder. I’m only good with the mechanical stuff and not computers so I should be able to help. If you’re sure the blue color smoke means oil, then it has to be along the line of the exhaust to the exhaust valve and near one or more cylinders itself… it can’t be the outside of the exhaust it has to be coming from inside the exhaust track. Right? Just here to learn. There’s no reason oil should get in the intake in any way… and you said the valve stem seals and PCV are likely good… then it could only be crankcase oil past the rings or excessive oil pressure or excess oil. When engines are pressure tested with oil it can be as simple as the camshaft lubricantion leaking and the engine will still run fine for a long time, but it’s just leaking oil into the non-friction spots of the cylinder head at an excessive rate… but that shouldn’t ever get into a cylinder - how could it?

 

Regarding your small oil leak: have you had the alternator gasket replaced yet? It's located toward the front of the engine on the driver's side. If not, that may well be the source of your leak.
Expensive labor-intensive PITA to get at it in order to swap out a cheap $5 part.