Three problems related to engine exhaust system have been reported for the 2005 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 GMC Yukon based on all problems reported for the 2005 Yukon.
1999 to present 4. 8,5. 3 5. 7,6. 0 liter engines from gm have inferior grade metal in the exhaust manifold bolts causing them to break. The vehicles will have exhaust leaks and false readings to the oxygen sensors. The exhaust leaks of raw exhaust gases in to the atmosphere translate to extra pollution into the atmosphere from all these vehicles . The other matter is that the computer on the vehicles isn't given the correct oxygen sensor reading because of the leaks ,either gas leaking out or air being drawn into the exhaust stream causing the premature failing of catalytic converters. The computer on the vehicles may or may not warm the customers with a light based on the severity of the exhaust stream leak gm put out replacement bolts for this problem ,but that only fixes the people's that have the time and or resources to visit the gm dealers. All the rest of the vehicles and their owners are responsible for getting the old bolts drilled out and trying to get the vehicles fixed on their own. Lots of pollution taking place and money being spent on a problem that could have been avoided with some proper grade fasteners. And this is on about 12,000,000 cars trucks and suvs. This is being written from someone who has had 25+ cars and has an automotive engineering background. And someone who spent money and precious time on this issue and really should not have had to.
2 bolts holding the manifold to the 6 l engine of my Yukon denali 2005 are broken. There is consequently gas emission leak at the source, not complying to resource emission laws, potential damage to the catalysor. At the garage, extended warranty refused to cover the bolt and work (but the manifold is) one of the bolt can not be drilled by the outside (no space) and has to be remove by removing the head cover. I am looking at a 10 hours estimate of labor.
Exhaust manifold bolt heads are breaking on my 2005 Yukon xl denali causing an exhaust leak, as well as engine error lights. GMC has denied knowledge of an issue, even though the problem seems wide spread. The bolts need to be removed and replaced. Very expensive repair.