need advice on smoking A4

[no1of consequence]

should i roll it or use a vaporizer? ;-)

any input appreciated, i'm trying to diagnose the car w/out pulling head off 
it. patient is a 98 a4 1.8t. quat, 5spd with 108k. it started smoking the 
other day, i noticed a puff at startup, and a bit thereatfer, after a minute 
or so it would stop. it pretty much never smokes when driving around.

now.. if i leave it idle for several minutes it will smoke consistently. a 
nice steady stream of whitish, acrid smelling smoke. it doesnt smell like 
coolant. no 'steamy' quality to the smell. on the road for a minute and the 
smoking stops. it seems once the car gets some air then no smoke.

i poked around tonight and found..
- plugs are furry white. i got the car a month ago so these could be 
original for all i know. pics at:
http://www.pbase.com/thejimrose/a4
- no oil in coolant that i can see. i assume i would see an oil slick when 
peering into the fill cap, no?
- no white foaminess on the oil fill cap. car uses a good bit of oil tho.. 
maybe 1/2 qt every 1k ?
- no oil in turbo outlet hose [that runs to the IC]. i didnt check the turbo 
intake hose [cold side]. does this mean the seals are ok? could the turbo 
seals be bad and pissing oil into the exh. manifold?
- air filter and airbox were immaculate.

i did just have the cat rewelded where the pipe tends to break coming out of 
the turbo. the top of the pipe was welded in the car. could htis have zapped 
the turbo seals? are welders meaningfully hotter than a spinning turbo? i 
really want this to be a turbo problem so i can replace it with a ko4 and 
not a motor problem, if that has any effect on the opinions. =)

help? thanx..
jim