How do u know if ur turbo is goin bad. My car is puffing white smoke out now i think the turbo is getting bad.

(WITH ENGINE OFF) You can remove the air filter intake pipe and see if you can move the compressor shaft. You're checking for any shaft play here. If you can wiggle the shaft and the blade can touch the opening, or if there's any sign of blade damage, then it's a pretty good indication that the turbo is going bad. Also, you might see engine oil in the intake pipe, which could be caused from bad seals.

Gotta add in this. I just bought a Turbo Magazine and it has a decent article on TURBO DEATH! Check it out it let's you know what to look out for.