ok here is what is happening, i own a 1990 cougar ls 3.8L and just recently the oil pressure has been dropping really low when im at a stop adn it has oil in it. adn now it is dropping low when im going under 30mph. i also just recently noticed a loud knocking noise coming from the drivers side valve cover. it knocks at idle adn when im drivign adn gets louder upon high rpms. does anyone have any ideas on what this problem could be?