What should I be looking for when I buy a used turbo, for example a used FP green?

I know look for shaft play, but is there anything else specific wise if there is unknown # of miles? How do you know if it needs a rebuild?

 

miles, shaft play, what kind of driving was it used for (street, drag, road course, etc), how much boost was ran on it, if it has ever been rebuilt (if so who did the rebuild), any cracks in the hotside as MHI housings, make sure none of the oil/water feed and returns don't leak, no chipped or damaged compressor or turbine wheels. I think thats pretty much everything

 

I wouldn't bother asking how much boost it was running, or what kind of driving it was used for, people lie. Also, 25psi of boost with decent boost leak is a lot higher shaft speed then just 25psi of boost, so its kind of useless info.

Make sre the turbine and compressor wheels don't show signs of hitting the housings. Make sure then turbine housing isn't cracked anywhere. The volute between the scrolls on a mitsu housing will almost always be cracked, so I really wouldn't worry about that. It usually just cracks and that's it. And check for signs of leaking, and shaft play. In/out shaft play is whats important, side to side, not so much.

 

Turbochargers are on the don't buy used list, IMO. They are just too sensitive to abuse and poor maintenance and there is nothing you can tell about the condition when you look at them other then obvious **** like broken studs and cracked housing.