B727-200 ON ILS TO RWY 11R AT 700 FT ABOVE GND GOT COMPUTER FLAGS ON BOTH FLT DIRECTORS. CONTINUED APCH USING RAW DATA. WHEN CLR OF CLOUDS AT 300 FT; EXECUTED MISSED APCH ACCOUNT OFFSET TO R OF CTRLINE. INDICATIONS HAD BEEN ON COURSE AND ON GS. MADE SUCCESSFUL APCH RWY 11L. ATIS EARLIER HAD SHOWN ILS RWY 11R OTS.

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ILS NORMAL UNTIL 700 FT ABOVE GND. RECEIVED COMPUTER FLAGS ON BOTH FLT DIRECTORS. RAW DATA LOC AND GS WERE NORMAL. CONTINUED APCH UNTIL ABOUT 300 FT AGL EXECUTED MISSED APCH BECAUSE ACFT WAS TOO FAR OFF COURSE TO THE R. LOC AND GS INDICATED ON COURSE AND ON GS. NO FLAGS; LOC OR GS WERE VISIBLE ON EITHER FLT DIRECTOR AND RAW DATA INDICATIONS INDICATED ACFT ON COURSE AND GS. I SPOKE WITH MSP TWR AFTER WE LANDED ON RWY 11L ON ANOTHER APCH; AND THEY INDICATED THEY RECEIVED NO WARNINGS THAT RWY 11R ILS WAS GIVING ERRONEOUS INFO DURING OUR APCH. SYNOPSIS: ILS RWY 11R WAS SENDING OUT ERRONEOUS INFO WITHOUT TRIGGERING WARNING SYS IN TWR OR OFF FLAGS IN ACFT. SUPPLEMENTAL INFO FROM ACN 353370: ARRIVING AT MSP; ATIS RPTED RWY 11R ILS OTS. AFTER BEING RELEASED FROM HOLDING; ATIS RPTED 800/1; THE RWY 11R ILS WAS NOT RPTED OTS. AT APPROX 400 FT AGL WE BROKE OUT AND IN LOW VISIBILITY SAW THE RWY 3 WING LENGTHS TO THE L. AT MINIMUMS; A MISSED APCH WAS INITIATED BUT NOT BEFORE 'WHOOP; WHOOP; TERRAIN.' THE GPWS AURAL WARNING WAS UNHEARD BY THE CAPT AND FO DUE TO THEIR INCREASED WORKLOAD DURING THE GAR AND THE TREMENDOUS NOISE OF THE WIPERS.