Piper Navajo PA-31 Service Manual page 526

PIPER NAVAJO SERVICE MANUAL
TABLE VIII-II. TROUBLESHOOTING CHART (TURBOCHARGER) (cont.)
Trouble
Cause
Remedy
Oil in induction housing.
Oil leaking past seal in
controllers.
Replace faulty controller.
Engine idles too slow - turbo
doesn't turn allowing oil to
leak from compressor seal.
Increase engine idle speed to
a maximum of 700 RPM, if
turbo still smokes, it must
be replaced. Note: New turbos
may smoke for a short period
of time.
White exhaust.
Leaking oil seal in turbine
(coked oil drain passages).
Engines idle too slow -
turbo not turning.
Jammed piston seal in by-
pass valve or bearing seizure.
Wastegate won't open.
Clean drain passages. It is
sometimes necessary to over-
haul or replace turbo.
Increase engine idle speed
to a maximum of 700 RPM,
if turbo still smokes, it must
be overhauled or replaced.
Remove and replace unit.
Clean return lines.
Clean line.
Replace linkage and adjust
wastegate to open and close
position to specifications
in overhaul manual.
Obstruction in oil outlet.
Blocked oil drain return line.
Broken linkage.
Controller malfunction.
Replace controller.
Wastegate won't close
completely.
Obstruction in oil inlet
orifice.
Replace controller.
Leaking valves in controller.
Piston seal in by-pass valve
worn or broken.
Broken linkage.
Replace controller.
Replace controller.
Repair linkage and adjust
wastegate to open or close
position to specifications in
overhaul manual.
POWER PLANT
Reissued: 10/12/79
2K4