Any trouble beyond scope of organizational
3-41. Troubleshooting
maintenance personnel shall be reported to direct
support maintenance.
Refer to table 3-3 for listing of possible malfunctions.
Table 3-3. Troubleshooting.
Malfunction
Probable cause
Corrective action
1.
Engine will not start
a. No fuel, or fuel shutoff valve
a. Open fuel shutoff valve, or fill tank.
closed
b. Low temperature.
c. Loss of fuel, or air leak
c. Tighten loose fuel connections. Prime
fuel system (fig. 2-28).
d. Defective batteries
e. Improper valve clearance.
2.
Engine hard to start
a. Air in fuel, or no fuel
a. Tighten loose connections, prime fuel
system (fig. 2-28) and service fuel tank.
b. Low ambient temperature.
c. Clogged air cleaner
3.
Engine starts but will not run,
a. Low on fuel
a. Service fuel tank.
or stalls frequently
b. Wrong type of fuel
b. Drain fuel tank and service with proper fuel.
c. Loss of fuel
c. Tighten loose fuel line connections then
prime system (para 3-71).
d. Fuel filters clogged.
e. Air cleaner clogged or defective.
defective air cleaner (para 3-65).
4.
Engine starts but misfires, or
a. Wrong fuel in tank
a. Drain tank and service with proper
vibrates excessively
grade fuel.
b. Fuel filters clogged.
c. Air cleaner clogged.
d. Fuel injector defective.
5.
Engine lacks power
a. Air cleaner clogged or damaged.
replace defective air cleaner (para 3-65).
b. Fuel filter, clogged or defective
defective filter (paras 3-68 and 3-69).
c. Defective fuel lines
c. Tighten loose lines or fittings. Replace
a defective line (para 3-67).
6.
Engine overheats
a. Loose fan belt
b. Obstructions in fins of radiator
b. Clean fins.
c. Collapsed hose or loose connections
c. Check condition of coolant hose. Tighten
loose connections, or replace defective
hose (para 3-98).
d. Low on coolant
e. Check oil level. Add when necessary
(LO 5-3810-206-12).
f.
Defective thermostat
f. Replace (para 3-98).
7.
Engine exhaust excessively
a. Air cleaner clogged.
smoky
b. Defective fuel injector
b. Replace (para 364).
8.
Engine clutch slips
a. Clutch out of adjustment
b. Linkage out of adjustment
9.
Engine clutch will not engage
a. Linkage out of adjustment
b. Clutch out of adjustment
c. Worn clutch
c. Report defect to general support maintenance.
10.
Engine temperature fails to
Defective thermostat (stuck open)
Replace (para 3-98).
raise
11.
Water temperature indicator
a. Loose electrical connection
a. Tighten all connections. Make good
inoperative.
ground.
c. Indicator defective.
3-42
