Through the cap in the valve cover.
4.5 to 5 quarts
yes
If its a V8, it's probably the oil pump pickup tube.
No, the ecm is set to operate only 6 cylinders, you need the ecm from the vehicle you got the engine from.
It sounds like the inside of the engine is so sludged up that the entire top of the head is covered.
According to the 1997 Mercury Grand Marquis owners manual : With engine oil filter change : ( 5.0 quarts / 4.7 liters of engine oil )
10w30
75w90 or 80w90
I put 10 w 40 in my 97 4.0 liter wrangler now it sounds diffrent. I think it should have had 10 w30 . Manual calls for 10w30
10w3010w30
It is important to know how much fluid to put into a cars engine. For a 1997 Jetta Vr6 needs about 5.3 quarts of engine oil.
The engine computer is also the regulator.