Color me confused: Volvo 850 Turbo content

So... my 850 Turbo has been puffing smoke in the last couple of months. I am trying to zero down the problem by process of elimination.

Problem: At start-up, warm up, warm running temperature, there is a small to medium amount of oil smoke generated and blown out of the exhaust. The amount of smoke varies on the angle of the driveway/parking lot. For example, Fit_Is-Slo's driveway is at an angle and I had the car nose forward with the tail going down hill. When I started it then, there was a "James Bond smoke screen" that blanketed the street. Today, on level ground, no where near as much smoke. There is oil consumption (obviously). More smoke is visible under load (which make me lean towards a bad turbo), but at idle, there is puffs of smoke (which makes me lean towards valve stem seals). I have pulled the dip-stick while at idle/warm and no smoke comes out.

What I have checked or has been changed: Anti Stance is the previous owner and has proof of the PVC box has been changed. So for the most part, I can scratch this off the list. Once it was warmed up and driven around the block, I pulled the intercooler line off coming off the turbo to the intercooler to check for oil, NONE. Only way to check the Valve Stem Seals is to pull the top portion of the head off and pull the cams and followers out. Don't have the tooling at my current location to do that.

Question is: From this, what is your guy's thoughts? I am planning on making a trip up to my Mum's house where there is enough tooling to do a Ferrari 355 belt change. My first thought is to pull the turbo off and look to see if the seals have gone to crap or there is some shaft play (though I would hear it, wouldn't I?). If the turbo looks good, then I'm going knuckles deep into the head. Thoughts?

Vacuum gauge.

I completely missed a TON of correct diags by not using one and eventually just fixed the vehicle through throwing on parts and asking others what they thought.

I had one Caravan that just out and out needed a new motor, but only after head gaskets, a few new rod bearings and valve seals.....

Oh, no codes thrown.

The possibilities:
Crank Case Ventilation smoke box (flame trap)
Turbo (seals and/or shaft)
Valve Stem Seals

Checking stem seals is as easy as pulling the exhaust manifold off and looking at the stems.

I have a 850 turbo and you are covering the bases. The only thing that pops to mind is the no oil on the inside of the inter cooler piping part. When the original 15g started to go a couple years back it didn't make any noise and there was not much shaft play upon inspection after removal. But the seals were shot and were letting a fair amount of oil into the inter cooler track. The oil did not show up right at the compressor outlet (too much velocity??) but there was plenty in the rest of the system and it would get sucked in when I jabbed at the throttle and other times too. There often is a weep hole at the bottom passenger side of the lower plastic tank of the intercooler. Is that area really really wet?

The turbo oil return line has a gasketed flange at the bottom of the turbo that leaks at the best of times and will make lots of (external) smoke as it drips on the downpipe if it is shot.

I was thinking about this a bit and the heavy smoke at an angle really does point at valve stem seals as the top end of exhaust valves would effectively get dunked in a tank of oil at a sufficient car angle with the flat topography of whiteblock heads.

If the smoke comes at random times in various quantities, and sometimes fogs the whole neighborhood, it needs a turbo.

I had a 5 cyl turbo in the shop that didn't smoke too badly, but when I was trying to track down an oil leak, it confused the E36 M3 out of me, because it seemed to be leaking from the exhaust manifold....turned out the stem seals were so bad the oil would run down when it was shut off, and then leak out past the not so perfect steel shim exhaust manifold gaskets. The owners complaint was a smell of burning oil on startup.

I think you probably need a turbocharger.

Slope effect.

Correct oil level ?

Aren't you going to be driving a company Ferrari soon and won't need to deal with such mundane issues?

In reply to Jeff:

One hopes.

In reply to iceracer:

Yes, oil level is always maintained. It gets low due to the consumption and you can hear the follower tick, but I make sure it's always up to snuff