The National Highway Traffic Safety Administration (NHTSA) has upgraded its investigation of possible engine problems involving 3.8-L V-6 engines used in Buick, Chevrolet, Pontiac and Oldsmobile vehicles built between 1996 and 2000.
NHTSA estimates as many as 2.3 million of the engines could have a fault that causes the engine to backfire while it is being started. The backfire can result in a cracked intake manifold that leaks gas onto the engine and ignites.
GM has already recalled more than 276,000 vehicles for a similar problem and denies there is a problem here, also noting that very few injuries have been reported.
