It seems that Isuzu had trouble deciding how long to offer a powertrain warranty on their products:

From '96 to '99 it was 6/60000

2000 to 2002 10/100000

2003 and on 7/75000

Unfortunitely I own a '99. I work for a manufacturer of Highway Equipment and if a customer was just out of warranty and thier motor failed we would replace it no questions asked, that is what good customer service is all about.

As for the warning signs, there weren't any at all. Oh wait, one comes to mind about 1 week prior to the motor FUBARing the engine oil light flickered. I checked the oil and it was fine so I figured it was just a glitch. Too bad it wasn't!