Piper Navajo Chieftain PA-31-350 Service Manual page 509

NAVAJO CHIEFTAIN SERVICE MANUAL
TABLE VIII-IV. TROUBLESHOOTING CHART (TURBOCHARGER) (cont)
Trouble
Cause Remedy
High deck pressure. (Com-
pressor discharge pres-
sure.) (cont.)
Controller return line
restricted.
Oil pressure too high.
Clean or replace line.
Check pressure 75 to 85
psi (80 psi desired) at
waste gate actuator inlet.
If pressure on outlet side
of actuator is too high,
have waste gate controller
adjusted.
Waste gate controller
malfunction.
Waste gate actuator piston
locked in full closed po-
sition. (Usually accom-
panied by oil leakage at
actuator drail line.) NOTE:
Waste gate normally closed
in idle and low power
conditions. Should open
when actuator inlet line
is disconnected.
Replace controller.
Remove and disassemble ac-
tuator, check condition of
piston and packing or re-
place actuator assembly.
Manifold pressure drops
as altitude increases.
(below 1500 feet.)
Oil in induction housing.
Malfunction of pressure
ratio controller.
Oil leaking past seal in
controllers.
Replace pressure ratio
controller.
Replace faulty controller.
Engine idles too slow -
turbo doesn't turn allow-
ing 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 tur-
bine (coked oil drain
passages).
Clean drain passages.
It is sometimes necessary
to overhaul or replace
turbo.
Reissued: 9/23/80
POWER PLANT
2J22