That smell and white smoke are from oil burning on the hot surfaces under your hood. You, my friend, have an oil leak. Unfortunately, leaking oil is just part of car ownership, especially when cars get older. Oil leaks can also stem from a loose seal somewhere. Check the seal around where your oil filter screws in to the car; that's where the big one was in my Celica and it was easily fixed by replacing the filter and tightening it when I put it back on. There are so many places oil can leak from, it may take some time, money and parts before the leaks are found and fixed. Aside from the cost of oil and the effect it can have on the environment when its dripping on to the ground, your car can run just fine while leaking oil, provided that you keep an eye on your oil level and top it off when needed.