Cbull
Active Member
Did a search for "oil leak" in RV-10 and returned nothing usable. Sorry if this has been hashed out before
I'm at a loss. I can't find an oil leak. New XIO-540-D4A5 with Hartzel Scimitar 3 blade prop, 60 hours on engine.
Noticed oil leak a week ago, but have noticed evidence of it on the top of the cowl for a long time. Small streaks going up cowl and onto the windscreen. Once it started pooling on my hangar floor it got my attention.
Decowled, washed down really well. Completely clean. Full static run up, with prop cycles in between. Let the oil get hot, 130. Found a few drips, but suspect they were from heating up the engine and the oil came out of places I couldn't clean well. Cleaned again, ran it again, no leaks can be found. Performed oil change, added 8 qts (she seems to like 6).
Flew today for an hour and again, oil dripping from cowl. Also need to mention oil is coming out of the two front intakes and flowing down front of cowling. Did the whole de cowl, clean, run up, clean again and on final run up, no leaks. Felt as much as the crank seal as I could get to, it was dry.
It seems to be wettest around front of engine, below all baffling. Dry as a bone on top. Oil pools on top of the air box. Bottom of engine completely coated. Lower cowl soaked as well.
Theories/guesses
#1 The breather tube faces forward, kinda odd. I guess the idea is to not face it rearward and create a suction. Is it possible ram air is coming from the bottom cowl where gear is and producing enough pressure in the case to make the crank seal leak? The slot around my front gear may be a little larger than normal. Because of the 3 blade prop. I do have a removable section for lowering cowl. I'd say 3" of clearance from front of gear to cowl.
#2 Is oil dropping out of breather tube, hitting cowl and weeping forward due to some weird turbulence inside the cowl. Again, there is oil coming out of the air intakes and flowing down front of cowl.
#3 on the last run there where small streaks on the back of the prop blades. Very small amount, may have been residual. Prop leaking...???
I'm at a loss. I can't find an oil leak. New XIO-540-D4A5 with Hartzel Scimitar 3 blade prop, 60 hours on engine.
Noticed oil leak a week ago, but have noticed evidence of it on the top of the cowl for a long time. Small streaks going up cowl and onto the windscreen. Once it started pooling on my hangar floor it got my attention.
Decowled, washed down really well. Completely clean. Full static run up, with prop cycles in between. Let the oil get hot, 130. Found a few drips, but suspect they were from heating up the engine and the oil came out of places I couldn't clean well. Cleaned again, ran it again, no leaks can be found. Performed oil change, added 8 qts (she seems to like 6).
Flew today for an hour and again, oil dripping from cowl. Also need to mention oil is coming out of the two front intakes and flowing down front of cowling. Did the whole de cowl, clean, run up, clean again and on final run up, no leaks. Felt as much as the crank seal as I could get to, it was dry.
It seems to be wettest around front of engine, below all baffling. Dry as a bone on top. Oil pools on top of the air box. Bottom of engine completely coated. Lower cowl soaked as well.
Theories/guesses
#1 The breather tube faces forward, kinda odd. I guess the idea is to not face it rearward and create a suction. Is it possible ram air is coming from the bottom cowl where gear is and producing enough pressure in the case to make the crank seal leak? The slot around my front gear may be a little larger than normal. Because of the 3 blade prop. I do have a removable section for lowering cowl. I'd say 3" of clearance from front of gear to cowl.
#2 Is oil dropping out of breather tube, hitting cowl and weeping forward due to some weird turbulence inside the cowl. Again, there is oil coming out of the air intakes and flowing down front of cowl.
#3 on the last run there where small streaks on the back of the prop blades. Very small amount, may have been residual. Prop leaking...???