One problem related to gas recirculation valve (egr valve) has been reported for the 2005 Chevrolet Silverado. The most recently reported issues are listed below.
Truck has 14000 miles, it has constant over heating problems while towing my 8k travel trailer. I have talked with the Chevrolet dealer about it, they told me that they were aware of the problem but at this time have no fix. I call stupid because I heard online that the 06 models have revised cooling systems and a larger turbo charger. My belief is the fix is to much $$ and they will only take care of the few people that tow and have issues. I have notice a lot of information on the net about 04. 5 and 05 lly duramax truck that tow over 10000 have this issue but my travel trailer fully loaded only weighs under 9k. The major down side is the trucks inability to maintain the speed limit due to the overheating water temperature and the power loss formed a cooling fan that runs hyperspeeds no stop when towing. My towing has been done at low outside temperatures ranging for 75 to 85 degrees outside. This truck is not performing as advertised or supposed to be designed for.