On the 1-2 and 2-3 shifts there is a rattling sound (or light knocking) sound coming from the engine. It sounds like noisy lifters. It occurs most of the time, but not all of the time.

- Tacoma, WA, USA

Engine stalled in traffic and idles rough on startup. Dealer reprogrammed idle control module. Engine surges and shakes under a load from power steering or alterantor. Dealer cleaned throttle body (only 4800 miles) and found large leak at evap vapor pipe. Continued to have problem. Dealership contact GM for help. GM replied that "4.2 liter motors have an inherent vibration at that speed." GM technical assistance also stated "engine surge under is normal under load by design." Car is ticking time bomb for another stall in traffic and daily endangers my family.

- Arlington, TX, USA

While driving vehicle stalled. The consumer restarted vehicle, and had the vehicle towed to the dealer for inspection. The mechanic could not duplicate the problem. The consumer informed the mechanic that this problem occurred more than once. There was no warning.

- Tryon, NC, USA

Vehicle looses power and the engine will not go above 2000 RPM. This is not fast enough to go through an intersection without being hit or side swiped. Provide further details.

- Abilene, TX, USA