wow... i had a similar experience....
i didnt have any immediate problems in the beginning, took it to a mechanic, said they cant see anything wrong. couple of weeks down the track, i got bad rattling sounds plus a whole lotta other things at aruond 2k. took it to a couple of mechanics, 3 to be exact. 2 of them said it mite be the turbo mite be busted and the vibrations are just coz of the turbo fins hitting the side of the housing and its reverberating through the engine.. lolz spent a whole lotta time changing turbo and wat not and then skip a couple of week, my engine blows. block blown open cabin filled with thick black smoke..oil, coolant and stuff all over the road.
turns out that one of the con rods were bent outta shape and was hitting the side of the block..
awsome experience, gave me a chance to yell out "its gonna blow!!!" and dive for cover. something i thought id never had to do.