We have a 1979 Dakota. Have owned since 2001. We have had an unusual sequence of events detailed here for comment.
When the engine reached 2300 hours, although it burned 1qt. Of oil for 10 hours and had good compression, we replaced it with a factory reman. Lycoming O-540. Oil cooler doesn't come with the new engine so we decided to replace it too with a remanufacture Pacific oil cooler. We flew the new engine for about 50 hours without any problem and then when retuning home to DXR asked for a practice approach. Too busy said ATC, so we landed uneventfully. When my partner in the right seat got out, he noted oil covering the bottom of the plane and the right fuselage as well. Three quarts remained when checked with the dipstick. Couldn't tell where leak was so added oil and restarted with cowl off and noted oil spray from mid portion of case of oil cooler. Not at a connection. Tiny crack in case. Spoke with Pacific oil coolers who sent us a new cooler gratis. It was replaced by our mechanic, carefully torqued etc..
25 hours later we were flying practice approached over Long Island sound to BDR. Landed and pulled off on taxiway to switch pilot to my partner who had been in the right seat. Took off and got about 5 miles from the airport at 3000 feet when I noticed that oil temp. On our JPS monitor (located in front of me in the right seat) was at top of scale. Told my partner who was flying who noted zero pressure in the standard left sided gauge. Declared an emergency, turned back toward BDR, reduced power slightly and landed on the runway, and got off the runway and shut down. Cowl off. Oil covered the right fuselage and bottom of the plane. No measurable oil in engine. Believe it or not, a fine crack was the source in our new Pacific oil cooler. This time when engine torn down by Lycoming, bearings, two connecting rods and other other damage found. Engine was factory rebuilt. Oil cooler replaced with a Niagara cooler with which we flew for about 300 hours without incident.
Last week my partner flew out of CQX with a friend. Heard a ? Faint noise at takeoff but plane flew fine and when they returned later to airport staff asked if "they had hit that seagull." Looked and there was bird debris on wheelpant. HOWEVER, when checking bird, partner noted oil on bottom of plane. He called me and said "are you sitting down?. Oil from the center area of the oil cooler. Tiny leak and appeared he had lost about 3/4 quart from what was present on preflight check.! Yes, we had a new oil cooler installed. Flies fine now.
All reported to FAA etc. in the second event and both first and second failed coolers checked out without any conclusion re: why they failed. Have since spoken with many pilots about our problems and have heard quite a few stories of others with cooler failures. Wonder how often they fail. Unless there is an "accident" (and none of ours qualify luckily), no one including rhe FAA know how common such failures are.
Anyone here had one?
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When the engine reached 2300 hours, although it burned 1qt. Of oil for 10 hours and had good compression, we replaced it with a factory reman. Lycoming O-540. Oil cooler doesn't come with the new engine so we decided to replace it too with a remanufacture Pacific oil cooler. We flew the new engine for about 50 hours without any problem and then when retuning home to DXR asked for a practice approach. Too busy said ATC, so we landed uneventfully. When my partner in the right seat got out, he noted oil covering the bottom of the plane and the right fuselage as well. Three quarts remained when checked with the dipstick. Couldn't tell where leak was so added oil and restarted with cowl off and noted oil spray from mid portion of case of oil cooler. Not at a connection. Tiny crack in case. Spoke with Pacific oil coolers who sent us a new cooler gratis. It was replaced by our mechanic, carefully torqued etc..
25 hours later we were flying practice approached over Long Island sound to BDR. Landed and pulled off on taxiway to switch pilot to my partner who had been in the right seat. Took off and got about 5 miles from the airport at 3000 feet when I noticed that oil temp. On our JPS monitor (located in front of me in the right seat) was at top of scale. Told my partner who was flying who noted zero pressure in the standard left sided gauge. Declared an emergency, turned back toward BDR, reduced power slightly and landed on the runway, and got off the runway and shut down. Cowl off. Oil covered the right fuselage and bottom of the plane. No measurable oil in engine. Believe it or not, a fine crack was the source in our new Pacific oil cooler. This time when engine torn down by Lycoming, bearings, two connecting rods and other other damage found. Engine was factory rebuilt. Oil cooler replaced with a Niagara cooler with which we flew for about 300 hours without incident.
Last week my partner flew out of CQX with a friend. Heard a ? Faint noise at takeoff but plane flew fine and when they returned later to airport staff asked if "they had hit that seagull." Looked and there was bird debris on wheelpant. HOWEVER, when checking bird, partner noted oil on bottom of plane. He called me and said "are you sitting down?. Oil from the center area of the oil cooler. Tiny leak and appeared he had lost about 3/4 quart from what was present on preflight check.! Yes, we had a new oil cooler installed. Flies fine now.
All reported to FAA etc. in the second event and both first and second failed coolers checked out without any conclusion re: why they failed. Have since spoken with many pilots about our problems and have heard quite a few stories of others with cooler failures. Wonder how often they fail. Unless there is an "accident" (and none of ours qualify luckily), no one including rhe FAA know how common such failures are.
Anyone here had one?
Sent from my iPad using Piper Forum
