Piper Navajo PA-31 Service Manual page 671

PIPER NAVAJO SERVICE MANUAL
TABLE X-II.
TROUBLESHOOTING CHART (INSTRUMENTS) (cont.)
Trouble
Cause
Remedy
ENGINE OIL PRESSURE GAUGE (cont.)
Excessive
pointer
oscillation.
Sluggish operation
or
pointer or pressure
fails to build up.
Improper
damping or
rough engine relief
valve.
Engine relief valve
open.
Disconnect line and
drain.
Check for leaks.
If trouble persists,
clean and adjust relief
valve.
Check and clean.
TACHOMETER
NOTE
Ascertain
that the drive cable from the
tachometer
will rotate properly.
engine to the
No reading on indi-
cator, either perman-
ent or intermittent.
Pointer oscillates
excessively.
Broken shaft.
Springs weak.
Rough spot on, or
sharp bend in shaft.
Replace instrument.
Replace instrument.
Repair or replace.
Excess friction
in
instrument.
Replace instrument.
INSTRUMENTS
Reissued: 10/12/79
3E9