Burning oil....sometimes, this is weird!?!

[Stabmasterflex]

So back story: i have a m20 turbo. Crankcase vented to atmosphere.
I start my car its fine. Let it run for a min or two then lots of smoke. Let it run for 10 min and the smokes gone and doesnt come back. Doesnt smell like coolant looks like burning oil. I thought i had blown an oil seal on the turbo so i swapped in another. Nope. Checked the plugs and they looked ok, no signs of oil and it idles and runs fine. I drained and measured my oil. I had 4.5l in it still (mind you i havent done much driving because of this). I was driving this car completely problem free this literally seemed to happen overnight. Any thoughts? Valve seals? Rings? Possible issue with the oil drain line? Also this is a turbo ix not sure if the oil pan configuration comes into play for a possible oil drain line issue. Thanks for any assistance.

[Stabmasterflex]

Oh forgot to mention, when i took off the old turbo the exhaust side as expected was soaked in oil and oil had pooled in the header tubes on cyl 5 and 6 (i figured it just drained down in there) im wondering if i turn off the car if its still feeding oil into the turbo for some strange reason then i start it and it gets hot enough to burn off the pool then its all good again? Ive been doing alot of thinking....some scratching.

[FLG]

If you blew a seal on the old turbo and it leaked a ton into the exhaust, you might still need to burn quite a bit of it out before it clears up. If the plugs have no signs of oil on em, id say it was/is your turbo.

[kamotors]

probably just the exhaust it full of oily soot if you replaced the turbo. I replaced my blown turbo(same symptoms as you) and the car still smoked the next time I drove it but eventually cleared out.

[Stabmasterflex]

So it turns out the oil drain line was too small. Was a 1/2" od line. Didnt cut it till it warmed up. I blocked the oil feed to the turbo and ran it up to temp. No smoke at all. I installed my new fittings and line today. Testing tomorrow.