Narrative:

While on localizer runway 26 approach to ZZZ1; I noticed the oil pressure indicator was showing no oil pressure. I declared an emergency and asked for vectors to the nearest airport and was vectored to 060 degrees and cleared to descend to 5000 ft MSL. I was in IMC at the time. Shortly thereafter; I started losing power and the tach slowed by about 300 RPM. At about that same time; the engine began making a loud; fast; regular knocking sound. Upon descending below 5000 ft MSL; I was in VMC and idented ZZZ at about my 12 O'clock position. At the instruction of ATC; I did a 360 degree to lose altitude and began a visual approach into ZZZ. After landing; I taxied to the ramp and shut down the engine. Other than the engine problems; no aircraft damage resulted and there were no injuries.

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Original NASA ASRS Text

Title: A PA28'S ENG OIL PRESSURE DROPPED DURING AN IMC APCH FOLLOWED BY A POWER LOSS. THE PILOT LANDED SAFELY AT A NEARBY ARPT.

Narrative: WHILE ON LOC RWY 26 APCH TO ZZZ1; I NOTICED THE OIL PRESSURE INDICATOR WAS SHOWING NO OIL PRESSURE. I DECLARED AN EMER AND ASKED FOR VECTORS TO THE NEAREST ARPT AND WAS VECTORED TO 060 DEGS AND CLRED TO DSND TO 5000 FT MSL. I WAS IN IMC AT THE TIME. SHORTLY THEREAFTER; I STARTED LOSING PWR AND THE TACH SLOWED BY ABOUT 300 RPM. AT ABOUT THAT SAME TIME; THE ENG BEGAN MAKING A LOUD; FAST; REGULAR KNOCKING SOUND. UPON DSNDING BELOW 5000 FT MSL; I WAS IN VMC AND IDENTED ZZZ AT ABOUT MY 12 O'CLOCK POS. AT THE INSTRUCTION OF ATC; I DID A 360 DEG TO LOSE ALT AND BEGAN A VISUAL APCH INTO ZZZ. AFTER LNDG; I TAXIED TO THE RAMP AND SHUT DOWN THE ENG. OTHER THAN THE ENG PROBS; NO ACFT DAMAGE RESULTED AND THERE WERE NO INJURIES.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.