Two problems related to coolant leaking have been reported for the 2005 Chevrolet Silverado. The most recently reported issues are listed below.
In June, 2011, I began noticing my antifreeze levels were dropping slightly. There were no noticable leaks of antifreeze anywhere. I attributed it to evaporation & added coolant. Over time the truck started using more & more antifreeze. A friend of mine noticed a puff of white smoke coming from the tailpipe. At the time I didn't really think anything of it. Last week while driving home from work after finishing up a "b" trick job (11pm), I noticed a knocking sound coming from the engine. It smoothed out after a few miles of driving it. The next day it happened again ( I work 26 miles from home) again it smoothed out & I was just grateful I got home safely that night. By this time I knew there were some serious issues & decided not to drive it again. I began researching the issue on line & found others that were experiencing identical symptoms. Turns out the problem lies with the cylinder heads in the engine manufactured for gm by castech. According to other people & by gms own admission, a faulty, weak material was used to build the cylinder heads. Over time the material wears away causing porous cracks & the antifreeze seeps into the oil system polluting it, causing significant damage to the engine. (by this time most extended warranties are up). The antifreeze mixes with the oil & is emitted out of the tailpipe as exhaust. This is why no traces of antifreeze were found & the reason for the white puff of smoke. Gm issued a bulletin #06-06-01-019b in June 2007 informing repair technicians on where to look for the damage. Through other peoples experiences, I am finding the engines were ruined in 90% of the cases & gm claims no responsibility. In my case I am driving a friend's vehicle waiting on word from my mechanic as to my options. These repairs are costly. Up to $5000 !! this is not from normal wear & tear this is a manufacturing defect & I feel a recall should be issued.
The contact owns a 2005 Chevrolet Silverado. The contact stated the vehicle was abnormally losing coolant every three weeks. The vehicle was taken to a local repair facility where the mechanic was unable to determine the source of the leak. The vehicle was not repaired. Neither the dealer nor the manufacturer was contacted in regards to the failure. The contact was concerned with the possibility of the vehicle overheating as he located numerous complaints online regarding the failure in his year, make and model but no recalls. The failure mileage was 80,000.