Broken or missing exhaust manifold bolts causing exhaust leaks. potential for carbon monoxide leaks into the driving compartment. upon researching on the internet this seems to be a very common and expensive problem. with gm engines from 1999 to around 2007. just found this problem on my 1999 silverado on 5/20/16. i have owned this truck since day one and have an excellent service record at a well know dealership. vehicle was stationary when the problem was diagnosed.
This truck has had an exhaust tic for many years. i just thought it was a lifter noise when in all reality while changing spark plug and wires about 2 months back i found the broken exhaust manifold bolts. upon further research on the web i found this is an issue on 80% of these gm trucks. i think there should be a recall because of possible carbon monoxide poisoning while operating these vehicles and the emission problems encountered. thank you for your attention to this issue. *tr