I have a 1981 pontiac grand prix 3.8 engine whats the name of the part the oil filter goes on im leaking oil behind that part and need to name what that part is called so i can replace it

Change it out

have a pressure test done so that you can see where it is leaking from.. If it is in the side of the block it may be a rusted welsh plug. Check inside the car for a leaking heater core and hoses . Check the drain hole under the water pump as it may be leaking from that hole while the pump is running ( water pump seal)

Right around 4 3/4 quarts. Use an AC Delco filter. There is a difference and this will prevent low oil pressure.

if it is not leaking then it is being burned by the engine, how many miles go by before you need to add oil?, if u are adding more than one quart every 1000 miles u have piston reing problems and or valve guide seal leaks. U won't see any smoke in most cases unless you are really going through the oil, like 1 quart every 300 miles.

Some K&N air filters are an "oil-soaked" filter and it is that oil that can cause the problem you are having. If you want to be sure, remove the filter, clear the code(s) then drive the car. If the code(s) do not return, install a non-oil-soaked filter.

Try some motor honey. It can be bought at most part stores, advanced auto, autozone, ect. It worked for my 95 Grand Am when I had a leak in my oil pan gasket. Hope this helps

It could be the oil pressure sensor for the oil light or guage.I have seen this before after age and heat plus vibration could cause it to crack and leak a lot of oil like you describe.Get it fixed asap.It should be easy to unscrew with a wrench or large socket .Buy the new sensor first though so you can replace it once you get the old one out.It leaks alot because of oil pressure from the oilpump pressurizes the rest of the engine bearings.It could break altogether and pump all your oil out and ruin your engine.

It could be the Oil pressure sensor is bad and leaking oil, There know to go bad and will leak worst when driving as the oil pressure goes up.
Good luck and hope this helps.

where did the leak come from?

its an oil pressure sender a common prob. and easy fix