Three problems related to manifold/header/muffler/tail pipe have been reported for the 1997 GMC Suburban. The most recently reported issues are listed below.
1997 GMC Suburban- multiple engine & transmission failures. At 60,000 miles, vehicle began to shift hard. Returned to shop for diagnosis and repairs several times for work. Finally, while driving the vehicle in city traffic, the transmission failed compeletly. Required valve cover and transmission rebuild @ cost of $2,000. On December 27 '03, had to replace the radiator. On Jan 17 '04, discovered that there was no antifreeze in new radiator. Returned to mechanic who replaced the radiator. Said the intake manifold needed to be replaced. Cost: ~$600. Took to another mechanic for second opinion. Same diagnosis. Both state that gm is aware of both problems, however, they will not cover the costs of repairs or replacement. Additionally- replaced alternator two times; replaced water pump two times; replaced the master cylinder in fall 2003.
Manifold gasket failed on my vehicle at 67,000 miles and probably well before this but I was not aware of the problem until picked up on routine maintenace check. Normally, I would fix the problem and move since I have gmpp (extended warranty) with no out of pocket costs. Not in this case. The problem here with the manifold gasket is not about noise pollution. It is about carbon monoxide and other noxious gas leaking into the vehicle. Before the lawyers at GMC pick up their pencils and start taking notes, the end result in my case was only one of feeling tired at the wheel. Problem solved when the new manifold gaskets were installed. Everyone happy, no accidents--not quite so fast. . Well here is the problem: I have been told that this problem is endemic to this series of vehicle and to be expected every 36,000. If true, then there are a lot of people driving 1997 and earlier GMC Suburbans around tired or worse. As a physician, I am well aware that the long term effects of exposure to low levels of vehicle emissions is unhealthy. I would like GMC to produce data to the NHTSA on the frequency of manifold gasket leaks in this series vehicle/engine, the liklihood of such leaks sending exhaust emissions into the vehicle and the probability of such leaks producing catastrophic results on the highway. The next time I pick up a paper and read that someone driving a GMC vehicle "fell asleep at the wheel" I would like to know that it was an accident unrelated to carbon monoxide poisoning.
On April 10, transmission failed and vehicle was returned to dealership. On April 18, the vehicle was returned to the owner after having replaced the transmission, the transmission cooler, and intake manifold gasket. On April 27, 2000, the engine failed on a busy road as schools were letting out. The engine failure, put both the occupants of the vehicle at risks and the schoolchildren also, as the engine failure resulted in loss of power steering and power brakes. The driver avoided collision but with no steering and loss of braking power, the results could have been catastrophic.