I rebuilt the 1g 4G63T in my Summit GTX 12 months ago (new rings, bearings and full head recon). Yesterday, it started running rough and blowing HUGE amounts of oil smoke, so I had it towed home. Good news is its not the turbo oil seals. Bad news is #2 compression is down to 65 from normal 85 psi and there's carbon build up on the plug. Odd thing is that after the tow home, the amount of oil smoke was reduced to puffs on revving.
So its looks like it's broken a ring: in any case the head has to come off so I can see how bad it is. With luck the bore will be OK and I'll put in a set of new pistons, otherwise it's a 040 oversize rebore.
In retrospect, I had noticed oil smoke on high boost and higher than expected oil consumption for a rebuilt engine. Most likely #2 ring lands were a bit too worn.
Oh well ... since it's all got to come out this is a good excuse to complete the AWD conversion.