CHAPTER 3. TROUBLESHOOTING - TM-9-2815-200-350071

CHAPTER 3

TROUBLESHOOTING

S e c t i o n I. GENERAL

for determining the trouble without completely

3-1. Purpose of Troubleshooting

disassembling the engine.

Note. Information in this chapter is for use of

3-2. General

Instructions

Direct Support and General Support main-

tenance personnel in conjunction with and as a

Note. This chapter contains inspection and

supplement to the troubleshooting section in the

t r o u b l e s h o o t i n g procedures to be performed

pertinent organizational manual (refer to Ap-

while a malfunctioning engine is still mounted in

pendix A). It provides the instructions where a

the vehicle and after it has been removed.

r e m e d y in t h e organizational maintenance

maintenance

manual refers t o s u p p o r t i n g

a. Visual inspections made while the engine is

personnel for corrective action.

mounted in the vehicle are performed before

attempting to operate the vehicle to avoid

a. Prevent Damage. Operation of a deadlined

damage or injury as well as to determine the

vehicle without a preliminary examination can

cause of the malfunctioning engine.

cause further damage to the engine and possible

b. T r o u b l e s h o o t i n g p e r f o r m e d w h i l e t h e

injury to personnel. By careful inspection and

engine is installed in the vehicle beyond the scope

troubleshooting, such damage and injury can be

of the using organization, is performed to

avoided. In addition, the cause of faulty

determine if the malfunction can be remedied

operation can often be determined without

without removing the engine from the vehicle,

extensive disassembly.

and, when subsequent removal is necessary, to

b. Precautions by Inspection. Most of the

indicate when repair can be made without

inspections are visual inspection and are to be

complete engine disassembly.

p e r f o r m ed before attempting to operate the

c. Troubleshooting a malfunctioning engine

vehicle. These inspections are mainly to

a f t e r it has been removed from the vehicle

determine the condition and to take precautions

c o n s i s t s o f subjecting it to tests on a

to prevent further damage.

d y n a m o m e t e r . This chapter discusses those

c. Troubleshooting While Mounted. T h e

s y m p t o m s which can be diagnosed by using

troubleshooting performed while the engine is

testing equipment, interprets results in terms of

mounted in the vehicle is that which is beyond

probable causes, and recommends appropriate

t h e normal scope of the using organization.

corrective action.

Check the troubleshooting section of the per-

d. Tests and adjustments prescribed for an

tinent organizational manual, then proceed as

engine after assembly (para 8-5) may be applied

outlined in this chapter.

t o the engine in w h i c h the malfunction is

d. Troubleshooting Engine only. If the engine

suspected. Particular attention should be given

only is received, inspection should be performed

to proper oil level, fuel pressures and proper

to verify the diagnosis made while the engine was

adjustments when operating the engine to

i n s t a l l e d in the vehicle. This inspection, to

determine appropriate corrective action to be

uncover further defects or to determine

taken for the malfunction.

malfunction, is important as it is the only means

Section II. TROUBLESHOOTING PROCEDURES

refer to pertinent manuals listed in paragraph 1-

3-3. General

2 4 . T h e p r o c e d u r e s f o r troubleshooting the

Most engine troubles are actually engine

engine assembly and the accessory systems are

accessory troubles. The troubleshooting portion

listed in paragraphs 3-4 through 3-11. Engine

of pertinent organizational maintenance

malfunctions are referenced to the appropriate

manuals, normally, will cover troubleshooting of

a c c e s s o r y system for corrective action, when

a l l engine accessories while mounted on the

applicable.

engine. For complete coverage of accessories,

3-1