Three problems related to engine and engine cooling have been reported for the 2005 GMC Sierra. The most recently reported issues are listed below.
Engine has lose of engine coolent over time with no evidence of leaks found. We brought the truck to a gm dealer which told us this was a known defect issue. They provided us with bullitin # 06-06-01-019b document id 1986750 which clearly state this was defect in the casting of the castech heads. The cost with parts and labor is $3,100. 00 dollars. Clearly, gm should cover this cost since this obviously is a known defect. Searching the internet you can see a large number of people experiencing this issue with little or no help from gm.
My vehicle was parked in my driveway. I was walking down the driveway and thought the car was being stolen as it was starting. There was no one in the car. The car did start several times on its own so I disconected the battery cable and had it serviced immediately. How long it had been doing this I do not know. I do know it had not been doing this on the previous day as I walk be there every day at least 2 times.
Truck was making a "knocking" noise upon start. Took to dealership mechanic and informed, based on the noise and where it's coming from, it's most likely a cracked cylinder and informed this is "common. " really?? will cost thousands to repair . . . Which I don't have. Frustrating to say the least. It has low miles, serviced regularly. If this is "common" why won't GMC step up and take care of it??.