Piper Navajo PA-31 Service Manual page 522

PIPER NAVAJO SERVICE MANUAL
TABLE VIII-II. TROUBLESHOOTING
CHART (ENGINE) (cont.)
Trouble
Cause
Remedy
Excessive oil consumption. Worn cylinder barrels or
piston rings.
Install new rings, deglaze
barrels.
Incorrect installation of
piston rings.
Failure of rings to seat.
(New nitrided cylinders.)
Worn valve guides.
Install new rings.
Use mineral base oil. Climb
to cruise altitude at full power
and operate at 75% cruise
power setting until oil con-
sumption stabilizes.
Replace.
High Cylinder Temperature.
Improper heat rating of
installed spark plugs.
See latest revision of Lycoming
S.I. 1042 for approved spark
plugs.
Cooling baffles missing,
broken or improperly installed.
Partially plugged fuel nozzles.
Improper I.D. of fuel lines
being used.
Engine improperly timed.
Engine being operated
excessively lean.
Mix control improperly rigged.
Insure that all baffles are un-
broken and properly installed.
Clean in MEK or Acetone and
blow out with compressed air.
Fuel line I.D. should be
.085-.090.
Check mag to engine timing
for correct use of degrees
B.T.C.
Do not go below minimum
fuel flows specified in
operator's manual.
Rig for complete travel.
NOTE
For a more in-depth guide to troubleshooting the engine, refer to the
latest revision of Avco-Lycoming Special Service Publication No.
SSP-475.
Revised: 9/24/81
POWER PLANT
2J24