Manifold/header/muffler/tail Pipe problems of the 2006 Chevrolet Silverado

Noticed a peculiar exhaust note somewhat like a tick that was reminescent of an exhaust leak. Took vehicle to local muffler exhaust shop and they inform me it is a manifold exhaust leak due to broken bolt(s) on the driver side. Was able to look for myself and I see one bolt head missing in the very back near the firewall.

2006 Chevrolet Silverado 1500 with 5. 3l v8 makes ticking noise when cold. Exhaust smell in passenger cabin. Noise decreases as engine hits normal operating temperature. After a service call to repair. The mechanic stated that the forward most and rear most exhaust manifold bolts were broken off inside the engine block on the driver side of the engine, this allows exhaust gas to excape when cold and accounts for exhaust smell in the cabin. Per the mechanic this is very common and should be a recall item.

There has been a long time problem of broken exhaust manifold bolts on 1999 to 2007 chevy Silverado and GMC sierra pickups. This problem is on 80 to 90 percent of the trucks with in them years this is millions of vehicles on the road. These vehicles should be recalled by general motors due to epa laws and emission standards not being able to be passed when these bolts break.

: the contact stated the vehicle had a defect in the exhaust pipe. The dealership made the repairs according to the general motors bulletin. After the repairs, the brackets were observed extended 3. 5 to 4 inches from the vehicles frame. This repair created a safety problem because the bracket could easily collide with road bumps. When the manufacturer and dealership were contacted both offered to return the exhaust pipe to its original status, which the contact considered unacceptable.