OIL FILTER CLOGGING.

Narrative

DURING ENG START THE R ENG 'OIL STRAINER CLOGGING' MESSAGE ILLUMINATED. THE OUTSIDE AIR TEMP WAS 20 DEGS F. THE ACFT HAD OVERNIGHTED ON THE RAMP IN BDL AND WAS COLD SOAKED. THE PLT OPERATING MANUAL STATED THIS WAS NOT ABNORMAL IN COLD WX AND THAT THE LIGHT SHOULD GO OUT WHEN THE OIL HAD WARMED SUFFICIENTLY. WITHIN 2 MINS THE LIGHT WENT OUT. IN CRUISE 1 HR AND 30 MINS INTO THE FLT; IN THE VICINITY OF GSO ARPT; THE R ENG 'OIL STRAINER CLOGGING' MESSAGE ILLUMINATED. FIRST INDICATIONS WERE 2 LOUD GRINDING NOISES ASSOCIATED WITH VIBRATIONS. THE FIRST GRINDING SOUND AND VIBRATION CONTINUED FOR ABOUT 3 SECONDS FOLLOWED BY A SECOND VIBRATION AND GRINDING SOUND OF APPROX 2 SECONDS. THE 2 INCIDENTS WERE 2-3 MINS APART. THE ONLY ABNORMAL INDICATION ON THE FLIGHT DECK WAS THE 'R OIL STRAINER CLOGGING' MESSAGE. ALL ENG INDICATIONS APPEARED NORMAL. THE FO AND I FOLLOWED THE PLT OPERATING MANUAL PROC FOR 'OIL STRAINER CLOGGING' MESSAGE INFLT. I INSTRUCTED THE FO TO NOTIFY FLT CTL AND LET THEM KNOW ABOUT OUR SIT AND THAT WE WOULD PERFORM A PRECAUTIONARY ENG SHUTDOWN AND WOULD NEED TO DIVERT TO THE NEAREST SUITABLE ARPT. GSO WAS DECIDED TO BE THE NEAREST SUITABLE ARPT. THE FO AND I COMPLETED THE ABNORMAL PROC AND THE COMPLETE ENG FAILURE/SHUTDOWN/DAMAGE CHKLIST. I DECLARED AN EMER WITH ATC AND REQUESTED A DIVERT TO GSO. A NORMAL SINGLE ENG APCH AND LNDG WERE MADE WITH NO SUBSEQUENT COMPLICATIONS. I DO NOT BELIEVE THE 2 OIL STRAINER LIGHTS WERE ASSOCIATED.