On a 1991 Mercury Cougar :
The oil pump is INSIDE the oil pan
( the oil pan is bolted to the bottom of the engine )
with a socket & wrench
According to my Chilton's Auto Repair Manual : For the 3.8 liter V6 engine in a 1991 Mercury Cougar : With engine oil filter change : ( 5.0 US. quarts )
What year is your cougar and also is it a V6 or a V8? This information would be nice to know :) it is attached to the engine
near the oil filter
I have a 1994 Mercury Cougar that runs good but burns alot of fuel and after the engine starts the and gets some heat, oil pressure gauge indicates low when there is nothing wrong. I have the same problem with a 1991 Mercury Cougar 3.8, doesn't burn fuel that much but a mechanician told me that it might be a miscontact on the gauge indicator, some dirt in oil pan blocking oil pump or the oil pump is going off. First thing to do is changing oil and filter replacing it by syntec oil in it so it will stay in engine more time when heating. If after that nothing changed check oil pressure at a local garage.
with your eyes
You need an oil change.
how do you change the oil pump on a 1991 s10 pickup
According to the 2000 Mercury Cougar owners manual ( 5W-30 ) for the four cylinder and V6 engines