My wife was driving the Shelby yesterday. She exited the freeway from about 70mph under coast, still in 6th, and as she approached the light noticed the engine stalled. She said there were no jerks, or noises, and she didn't even notice it stalled until she noticed the charge (battery) light and oil light on. She restarted with no issues and waited for the green light. She said when she started to accelerate, gently now being nervous, and hit 2nd at about 15-20 mph the car began to "rock". She described it as a back and forth motion from left front to right rear, similar to the wind draft you might feel off of a semi, or a knot on a tire. She said it was very rythmic, and not abrupt, but steady. She limped it into a parking lot, checked the tires, and the fluids and nothing seemed abnormal. She drove it about 3/4 mile home in second at 20 with no issues. I came home and checked the car over and drove it progressively more aggressive and noticed nothing. The only slightly abnormal things I can see are slightly low brake fluid, and the inside edge of the front tires badly worn from too much negative camber. I did, now that I'm scrutinizing, notice some tapping from the inside edge of the valve covers, but sounded like it was coming more from the area of the injectors. Not sure if that's normal. Do these things have a "noisy" valve train or injectors?
