signs of a dieing turbo?

[zaebst]

i couldn't find any straight forward answers searching through the forums on this so here's the deal, i've been running the stock 14b with a ported compressor housing. if possible, i believe it has a good 175k miles on it or so by now. (bought the car back from a friend recently) the engine only has 15k on the rebuild and i just compression tested it and it had perfect 160 on all four (it has new 1g pistons) everything is perfectly dry and no leaks or anything anywhere. with that said, my car uses a lot of oil. say on average a quart every 400 miles or so or more. it's not blowing oil out the exhaust and if i rev it while sitting there i only get black smoke. but when i make an actual run with it the boost drops from 16 to about 7 at 5500 rpms and kinda hangs there to redline. also, and only when driving under full boost, it gets a puff of oil smoke. now seeing as i've never encountered any of these sort of things i've gotta say that the turbo is dieing. i'm getting my stock 16g off my laser and putting that on to see if it (theoretically) solves the problem. does this sound like i'm heading in the right direction with this?
thanks in advance for any insight or pointers on my situation

 

[TurBoGs-T]

Did you check for play in the turbo??

 

[BUCK]

All I can offer is that my 14B doesn't drop off boost at redline - holds 14-15 psi. Yours sounds like a great car worthy of a new 16g maybe?

 

[zaebst]

yeah it has no shaft play at all. my buddy kept telling me it's the best 14b he's ever seen and he's been into dsms for more than 3 years and is on his second 14b right now running 20psi. also, i've found that when i set the boost down a little at 14.5 it runs absolutly perfect. (with the rewired stock pump). i double checked all my vacuum caps and all of the icp connections when i put my intake back on after we all checked the turbo for shaft play. and now at 14.5 everything runs perfect all the time? yet it's still using a little oil. i'd say after last night of running it hard for a few hours driving around it used a 1/4-1/3 quart. that was about 100 miles. the only thing left i can think of is that the pvc valve is defective (just bought a new little fram one when i did the valve cover gasket). the valve cover has a little baby k&n breather also instead of the stock intake return line. any ideas anybody?