A rattling / mechanical noise that occurs for about 30 seconds after shifting to drive or reverse. The noise only occurs when the car has not been started for several hours or when it has set overnight. I can stop the engine, restart and the noise is not there. This condition was first noticed after a GM dealer change fluid about 9 months ago. Since that occasion, i recently had the transmission drained, filter replaced and refilled with new fluid. The shop that changed fluid, reports no debris was found in the screen or on the pan magnet and the mechanic is convinced the transmission is in good shape. They think the noise is coming from an unknown location which they have been unable to locate. To me, the sound seems to go away after something in the engine or transmission "pumps up", or develops pressure in an unknown mechanical / hydraulic system, possibly the torque converter?? Thanks
Oct 12, 2015 at 1:36 PM
