1. Insufficient oil. 1. Fill oil sump or tank to proper level. 1. NOTE: Make sure you are using the
correct grade and weight of oil. 2. Pressure relief out of adjustment. 2. Adjust oil pressure to proper limits. 2. On external adjustable type increase
oil pressure by turning adjusting
screw clockwise, and to decrease
turn counterclockwise. On types
with solid tower standard ¼ inch flat
washers are used to control oil
pressure. Add washers to increase
oil pressure and remove washers to
decrease oil pressure. On short
tower, a maximum of three washers
may be used – on a tall tower, a
maximum of nine washers may be
used.
3. Dirt or metal chips under oil
pressure relief valve.
3. Remove, disassemble, and clean. 3. Solution is selfexplanatory.
4. Damaged oil pressure relief seat. 4. Replace or repair. 4. On engines with the removable seat, seat may be pulled out and another
pressed into place. On engines that
have seat machined in the case,
repairs must be made by repairing
existing seat with Special Tools ST 243, ST248 and ST340 that make
up the reseating tool assembly.
(Refer to latest revision of Service
Instruction No. 1172.)
5. High oil temperature. 5. Check all areas that involve lube
system and lube oil cooling system.
5. Inspect the following areas for
trouble: (a) Proper oil level. (b)
Proper grade and weight of oil. (c)
Thermostatic bypass valve working
properly and seating squarely. (d)
Plugged or partially plugged oil
cooler lines or oil cooler. (e)
Excessive blowby. (f) Air duct to
cooler blocked or cooler partially
covered. (g) Defective temperature
gage. 6. Restriction at inlet side of oil pump. 6. Remove and clean oil suction screen
and oil passage to inlet side of oil
pump, if necessary.
6. Solution is selfexplanatory.
7. Excessive internal spill off of oil. 7. Check the following areas for
excessive oil flow and repair or
replace. (a) Loose or missing plugs
in oil galley. (b) Piston cooling
squirts blocked open. NOTE: Low
oil pressure usually occurs at low or
idle RPM. (c) Excessive bearing
clearance. (d) Cracked crankcase in
area of oil galley.
7. Solution is selfexplanatory.