VG-21 Squadron

Maintenance Items

MAINTENANCE ITEM # 24  [July 2009]

Lee Beery


This maintenance item deals with an engine oil leak.  Not the everyday oil leak, a strange one and it was our plane so I have first hand knowledge of what happened.  I first noticed a strong engine or exhaust odor on climb out.  I first checked for an open hose in the cabin heat system.  Everything was fine.  Then I noticed an oil trail com ing from the hinge line on the left side of the upper cowling and a little on the front of the engine case.  At this point, I was positive that the crank case seal was leaking.  To make sure I was correct, I washed the engine with solvent to remove the oil and while the engine was wet with solvent, I dusted the area with baby talcum powder.  I then made a test flight and rechecked the area for the source of the oil.


The oil was com ing out of the engine as vapors between the engine case halves about 2” aft of the front seal area.  This indicated the case was pressurized.  What I found was the crank case vent tube was plugged with mud.  We do have problems with mud dauber wasps in our area.  It wasn’t long ago that the mud daubers plugged the fuel vent tee located on the bottom of the fuselage.  After clearing the vent tube and re-torque of the engine case bolts, the engine is once again, dry.  No more oil leaks.