buick century

i have a 87 buick century 2.8 engine it is having trouble running right some one told me it is the coil pack it dont have any speed hardely at all and now when i drive it pecks and pings and it stalles in reverse and theoil light comes on and it has oil

Hold off on the coil pack. That could be the problem but your discription is lacking detail. Does it do this as soon as you start it or does it run fine until warm? Have you tried any repairs so far? It so What have you done or replaced?

i changed the coil pack and it runs a little better and it has better speed and goes up hills better
but after it runs awhile it starts knocking and the oil light comes on and it starts running hot for some reason

Check the connection on the oil sending unit. If this car looses oil pressure the spark will shut off. It can cause it to sputter as the pressure dances around the cutoff point. Knocking can be caused by overheating as the oil gets thinner with temp. Also bad plug wires will often be worse when hot. Also check your crank position sensor, these too can be temperature sensitive.

where on the engine are these things at

I think you will need to buy a Haynes or Chiltons manual. You can get one at any autoparts store. It will have photos, drawings, and well written instructions.

thanks much i will check that out