I bought a used turbo off ebay.

The compressor housing is dirty and old looking.
How can i clean and polish it up to look brand new?

 

Take off the housing, go to town with some sand paper or any number of media wheels, once you get the bulk of it smooth, go to a higher grit, repeat the sanding... keep going higher grit until your satisfied with the finish, then polish out with a aluminum/ metal polishing compound.

 

That will work for polishing it,

If you are just wanting to clean it up, use some spray engine degreaser. The 'gel' kind works great. spray it on there and rub circles with a shop towel, wipe dry, looks like new.

 

media blast it. tape it up REALLY good blast it good then clean off with brake clean and compressed air. Obviously you will want to remove compressor housing

 

yeah media blast it with glass bead. alum looks good after that

 

If the aluminum is just dirty and not pitted, I have had really good luck with walnut shell or corncob. I used walnut shell to clean up a bunch of aluminum parts for my b18 and they come out looking like a fresh casting.

 

Hum.. Really?

 

whatever you do, just make sure to remove the housing, you dont want anything inside the turbo. and dont blast any of the inside surfaces

 

Just make sure you don't turn the pressure up to high or it will take some aluminum with the dirt.

Also as mentioned by BailHatch Walnut shells work great on aluminum in place of the glass beads and you don't have to worry about it removing material!!

 

would sanding it smooth and polishing it make it look like

 

yes but do you have the paience to do that, because it is alot of work and you have to do it several time with finer and finer grit before you finally finish it with polish. IMO a half assed attempt to polish it will make it look worse than a dirty housing. Im warning you its alot of work to polish a piece of metal to a shine evenly