EchoDelta
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Our NA Arrow IV is in the shop for its annual. The IA doing the inspection called with some worrisome news. Aside from the usual list of minor issues, when they cut open the oil filter they discovered a moderate amount of what they determined to be steel shavings. There were more in the oil screen (but no chunks). The filter was only 10 hours old, having been changed when we did an oi change about 6 weeks ago. At that time we did an oil analysis, but did not cut open the old filter, That most recent oil analysis showed normal levels of all tested metals, although the readings for iron have been rising a bit over the last 3-4 samplings dating back a couple of years.
This is a factory rebuilt ("zero time") Lycoming IO-360-C1C6 with about 1570 hours. We got it just before Lycoming introduced the roller tappets, so it has the older solid type tappets. It has never had any serious maintenance issues and seems to be running well. (Our previous engine went well over 2000 hours and never "made metal.") The plane is flown conservatively by experienced pilots. We did install a SureFly EIS a couple of years ago, but nobody thinks that has anything to do with this problem. For the past several years we have been using exclusively Phillips X/C 20W50 and change the oil and filter every 40-50 hours. The plane is hangared and flown regularly, rarely going more than two weeks between flights.
The shop doing the annual is the same one we have used for the past 20 years and they are absolutely first rate. The IA doing the inspection consulted with his boss, the head of maintenance, and together they suspect that the metal is from the camshaft lobes. They say they and other shops are seeing a lot of camshaft problems in Lycoming engines at around 1500 hours, but rarely on ones that get used regularly. They think there is an outside chance that this was a one-off event. Their recommendation (and Lycoming's), which my co-owner and I accepted, is to fly another 10 hours and again check the oil filter. If there is more steel then the option (short of an overhaul or engine swap) is to pull the #2 cylinder and have a look at the camshaft.
Any comments or recommendations are welcome.
This is a factory rebuilt ("zero time") Lycoming IO-360-C1C6 with about 1570 hours. We got it just before Lycoming introduced the roller tappets, so it has the older solid type tappets. It has never had any serious maintenance issues and seems to be running well. (Our previous engine went well over 2000 hours and never "made metal.") The plane is flown conservatively by experienced pilots. We did install a SureFly EIS a couple of years ago, but nobody thinks that has anything to do with this problem. For the past several years we have been using exclusively Phillips X/C 20W50 and change the oil and filter every 40-50 hours. The plane is hangared and flown regularly, rarely going more than two weeks between flights.
The shop doing the annual is the same one we have used for the past 20 years and they are absolutely first rate. The IA doing the inspection consulted with his boss, the head of maintenance, and together they suspect that the metal is from the camshaft lobes. They say they and other shops are seeing a lot of camshaft problems in Lycoming engines at around 1500 hours, but rarely on ones that get used regularly. They think there is an outside chance that this was a one-off event. Their recommendation (and Lycoming's), which my co-owner and I accepted, is to fly another 10 hours and again check the oil filter. If there is more steel then the option (short of an overhaul or engine swap) is to pull the #2 cylinder and have a look at the camshaft.
Any comments or recommendations are welcome.
