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6.1 ENGINE TROUBLESHOOTING
The following troubleshooting chart is to be used to
isolate engine problems and give possible causes and
corrective action responses.
The troubleshooting key is generic and can be used for
several types of engines. Use only those possible
causes and corrective actions that apply to the
unit.
SECTION 6 - ENGINE
TROUBLE POSSIBLE CAUSES
(Refer to Key Below)
CORRECTIVE ACTION
Black Exhaust 1, 20, 22, 25, 29, 31, 32, 33 repair or replace
Blue/White Exhaust 4, 20, 25, 31, 33, 34 repair or replace
Difficult Starting 1, 5, 7, 8, 10, 20, 21, 22, 29, 31, 32, 33 repair or replace
Erratic Running 1, 7, 8, 10, 20, 21, 23, 26, 29, 33, 59, 62 repair or replace
Excessive Fuel Consumption 1, 20, 22, 23, 25, 39, 31, 32, 33 repair or replace
High Oil Pressure 4, 41 repair or replace
Knocking 22, 26, 29, 31, 33, 36, 46, 59 repair or replace
Loss of Power or System 1, 8, 10, 20, 21, 22, 23, 25, 26, 31, 32, 33 repair or replace
Low Cranking Power 2, 3, 4 repair or replace
Low Oil Pressure 4, 36, 37, 39 repair or replace
Misfiring 10, 20, 25, 26, 28, 29, 32 repair or replace
Overheating 1, 19, 25, repair or replace
Poor Compression 25, 28, 29, 31, 32, 33, 34,59, repair or replace
Starts and Stops 1, 6, 10, 62 repair or replace
see electrical systems
see engine service manual
Vibration 20, 23, 25, 26, 29, 33, 49 repair or replace
Will Not Crank 2, 11 charge battery or replace
Will Not Start 1, 10, 62 repair or replace
see electrical systems
see engine service manual
TROUBLESHOOTING KEY
1 Restriction in air cleaner 22 Incorrect grade of fuel 43 Faulty suction pipe
2 Bad electrical connection 23 Sticking throttle/restricted movement 44 Choked oil filter
3 Faulty starter motor 24 Exhaust pipe restriction 45 Bad solenoid switch
4 Incorrect grade of lubricating oil 25 Leaking cylinder head gasket 46 Incorrect piston height
5 Low cranking speed 26 Overheating 47 Damaged fan
6 Fuel tank empty 27 Cold running 48 Faulty engine mounting
7 Controls not in correct
operation position
28 Incorrect tappet adjustment 49 Incorrectly aligned flywheel and/or
flywheel housing
8 Blocked fuel feed line 29 Sticking valves 50 Faulty thermostat
9 Faulty fuel lift pump 30 Incorrect high pressure pipes 51 Restriction in water jacket
10 Choked fuel filter 31 Worn cylinder bores 52 Loose fan belt
11 Battery capacity low 32 Pitted valves and seats 53 Choked radiator
12 Air in fuel system 33 Broken, worn or sticking piston ring(s) 54 Faulty water pump
13 Faulty fuel injection pump 34 Worn valve stems and guides 55 Choked breather pipe
14 Faulty fuel injectors or incorrect
type
35 Restriction in air cleaner 56 Damaged valve stem oil deflector (if
fitted)
15 Incorrect use of cold start
equipment
36 Worn or damaged bearings 57 Coolant level too low
16 Faulty cold start equipment 37 Insufficient oil in sump 58 Blocked sump strainer
17 Broken fuel injection pump
drive
38 Bad/defective oil temperature switch 59 Broken valve spring
18 Incorrect fuel pump timing 39 Oil pump worn 60 Exhaust or vacuum pipe leak
19 Incorrect valve timing 40 Pressure relief valve sticking open 61 Bad or defective water temperature
switch
20 Poor compression 41 Pressure relief valve sticking closed 62 Bad spark plug(s)
21 Blocked fuel tank vent 42 Broken relief valve spring