TM 9-2320-387-24-2
Change 1
14-1
CHAPTER 14
TROUBLESHOOTING (DS/GS)
Section I. MECHANICAL TROUBLESHOOTING
14-1. GENERAL
14-2. MECHANICAL TROUBLESHOOTING INSTRUCTIONS
a. The troubleshooting procedures in this section cannot give answers to every possible vehicle malfunction
encountered. However, the procedures do list the most common answers to a problem in an organized step-by-
step study. Faults are listed in the order they are most likely to occur, and instruction directs tests and
inspections toward the source of a problem and successful correction.
CAUTION
Operation of a deadlined vehicle without preliminary inspection
could cause further damage.
b. Do the easiest things first. Look for the most obvious cause to a problem. For example:
(1) Excessive oil consumption may be the result of leaks at gaskets or loose line connections.
(2) Always check the easiest and most obvious things first. This simple rule saves time and trouble.
c. Doublecheck diagnosis before disassembly. The source of most engine problems can be traced to more
than one part in a system. For example:
(1) Excessive fuel consumption may not be caused by the fuel pump alone. Instead, the trouble could be a
clogged air cleaner or a restricted exhaust passage causing severe back pressure.
(2) Engines are often disassembled in search of a problem and the real evidence of the problem is
destroyed. Check again to be sure an easier solution to the problem has not been overlooked.
d. Before correcting a problem, diagnose the cause of the problem. Do not allow the same failure to occur again.
Information in this section is for use by support maintenance personnel in conjunction with, and as a
supplement to, troubleshooting procedures in chapter 2.
TROUBLESHOOTING
MALFUNCTION
MECHANICAL
PROCEDURE
NO.
MALFUNCTION
PAGE
ENGINE
1.
Engine will not crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-3
2.
Engine cranks but will not start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-3
3.
Engine stops during normal operation . . . . . . . . . . . . . . . . . . . . . . . . . .
14-4
4.
Engine knocks (mechanical noise) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-4
5.
Excessive oil loss or consumption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-4
5.1.
Injection pump leaks fuel from throttle shaft . . . . . . . . . . . . . . . . . . . . .
14-4
6.
Low oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-4
7.
Excessive engine vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-5
8.
Excessive exhaust smoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-5
9.
Accelerator pedal sticks or full throttle cannot be obtained . . . . . . . . . . .
14-6
10.
Leaking exhaust gases or exhaust noises . . . . . . . . . . . . . . . . . . . . . . . .
14-6
11.
Loss of coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-6
12.
Engine overheats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-6
13.
Engine does not develop full power . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-6
14.
Crankcase oil diluted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-7
15.
Engine fails to stop with rotary switch off . . . . . . . . . . . . . . . . . . . . . . .
14-7
TROUBLESHOOTING SYMPTOM INDEX
