Volvo: S80 T6 Turbocharger Bearing Leak, volvo s80 t6, coolant lines

Question
Hows it going man. I have a problem, recently I purchased a 2000 Volvo S80 T6 with 76,000 miles on it. An hour after having it, the oil light came on and in short the oil sump and pump seal assembly or something in that nature had to be replaced - $1100 at a volvo dealership. Upon getting my car back, it was pumping white smoke out of the tailpipe, and after making phone calls I determined that both turbocharger's bearings were destroyed in the oil problem. After a $3650 quote from the volvo dealer, I tracked down a pair used from a wrecked car with 65,000 miles on it for $800. The new ones had no play in the turbo shafts, as the old ones did. I replaced them myself after many hours in my garage, and started the engine. I tested for oil flow by loosening the oil feed line bolts, and oil pumped out of both of them, plenty of oil. I also tested the coolant lines, and both lines seemed fine. I took the car out for a drive, and drove it easy. For 5 miles, it seemed fine. No smoke and plenty of power, and no leaks. After about 5 miles however, white smoke started pouring out of the tail pipe. In disbelief, I pulled over and switched off the engine. After staring at the vehicle for about ten minutes, I started the engine, and there was no smoke. I drove it another mile, and smoke came out again. Do you have any ideas on what this problem might be? I was thinking it was coolant but that tested fine. How long does it take to blow these turbos? Can they be destroyed in 5 miles of easy driving? What can I be missing? I would buy new ones but I fear that I will just destroy those too. Please help in any way you can, this has been nothing but a nightmare, I would greatly appreciate it.

Answer
Kevin,
I would say that a few minutes of running/driving should not blow a turbo.
As far as the white smoke, that generally means coolant. You may have an internal coolant leak to the combustion chamber. Sometimes that will show up by looking at the plugs and seeing if one is "super clean". Like it was steamed cleaned. You may need to have a compression test and cylinder leakage test to help diagnosis the problem. You say that after a few miles of driving it begins to smoke. It might take some running time to heat things up enough to open that area that leaks. Like a leaky head gasket or cracked head.