low oil pressure and knock

this mornin when i went to go to school i started my car and it started knocking really bad so i shut it off and took him to school and came back and checked the oil and it was a little low so i filled it up and it eventually went away so i drove it a little and came back and took a truck to be on the same side. When i got back from school i asked dad bout it and he said dont worry bout it just switch to high milage 10w 40 oil. i use castrol gtx 10w 30 now with a motercraft filter and it hasnt been 1,000 miles since the oil change and the last couple of weeks the oil pressure gauge has been readin low closer to the n on the gauge when it used to carry around the m on the gauge it has about 88,xxx miles on it so what should i do? any help would be great thanks in advance

Sometimes running a higher octane fuel in your car can help to eliminate early signs of knocking (I can't give you the specifics as why, just know it to be somewhat true from experience). It's an inexpensive check if anything.

Sounds more like a spun bearing/rod knock than a fuel issue.

ok thanks guys i started it later on and it didnt knock but it didnt carry much oil pressure i forgot to include its the 4.6L V8 in a 94 LX

I have a '95 -bird and I recently expierienced a knock and with my luck it just so happened to be a connecting rod bearing (ouch!). If it knocks at low RPM til warm and also at about 2500 to 3000 then there is a good chance it's the same prob. I'd say take it to an engine shop to get it properly diagnosed.