1996 Plymouth Neon engine knock?

I have a 96 Neon with 110,000 miles on it and recently I can hear an engine knock while accelerating from a stop. While car is idling, no knock is present. Pressing on the throttle while in park only generates a slight knock at about 3000 rpms. Been real good about changing oil every 3000 miles, although it is due for a change now. Engine burns a little oil (about 1 oz. per week) on about 300 miles of freeway driving. Been a good car and would like to keep it a while longer. Sound like a major repair or something simple?