One problem related to engine cooling system has been reported for the 2005 Chevrolet C/k 3500. The most recently reported issues are listed below.
I believe my 2005 Chevrolet silverado 3500, duramax/allison was equiped with under designed cooling systems; both transmission and engine. On slow mountain type roads I can run my unloaded truck into near overheat conditions. I believe these issues may be common to other '04. 5 and '05 lly gm and Chevrolet trucks like mine and gm has not provided it's dealer network with solutions to remedy the problem (most of them are simple, that the other 2 majors seem to understand: air flow control throught the cooling stack and cold air to the intake).