I have a 96 Pontiac Grand Am Se 2dr 6cy 2.4 liter that has about 70k on it . I have kept regular maintenance on the vehicle, (tunes-ups,oil changes etc.) On a cold start the engines sounds like a diesel until i run about a block or two and then the sound goes away but I am wondering if this is portending a future problem or not. What is causing this and how can I fix it if posseble and also I'd like to know just how much milelage I can reasonably expect to get from a 1996 Pontiac Grand Am with proper maintenance. Your prompt replies will be appreciated.