What was found
CREW ENTERED A DESCENT FROM 8,000 FT. PULLED POWER BACK TO 80 PERCENT N2 AND THE LT ENGINE OIL PRESSURE POINTER WENT INTO THE RED AND INDICATED 40 PSI. PILOT INCREASED POWER ON LT ENGINE TO 82 PERCENT AND THE POINTER WENT INTO THE GREEN. CREW RAN QRH AND RAN CHECKLIST FOR LOW OIL PRESSURE INDICATION. WHILE READING CHECKLIST THE POINTER WENT INTO THE RED AGAIN. CREW THEN DECLARED AN EMERGENCY AND RECEIVED PRIORITY FOR RUNWAY 4. CREW CONTINUED THE CHECKLIST WHICH INSTRUCTED THEM TO REDUCE POWER BELOW 80 PERCENT N2. CHECKLIST WAS COMPLETED THE OIL PRESSURE REMAINED IN THE GREEN AND THEY LANDED WITHOUT INCIDENT.