SECTION 5 - ENGINE

5.1 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.

TROUBLE

POSSIBLE CAUSES

CORRECTIVE ACTION

 

(Refer to Key Below)

 

 

 

 

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, 9, 10, 20, 21, 22, 29, 31, 32, 33

repair or replace

 

 

 

Erratic Running

1, 7, 8, 9, 10, 20, 21, 23, 26, 29, 33, 59, 62

repair or replace

 

 

 

Excessive Fuel Consumption

1, 20, 22, 23, 25, 29, 31, 32, 33

repair or replace

 

 

 

Excessive Crankcase Pressure

25, 31, 33, 34, 45, 55

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, 11

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, 45, 49

repair or replace

 

 

 

Will Not Crank

2, 11, 45

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

28

Incorrect tappet adjustment

49

Incorrectly aligned flywheel and/or

 

operation position

 

 

 

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

35

Restriction in air cleaner

56

Damaged valve stem oil deflector (if

 

type

 

 

 

fitted)

15

Incorrect use of cold start

36

Worn or damaged bearings

57

Coolant level too low

 

equipment

 

 

 

 

16

Faulty cold start equipment

37

Insufficient oil in sump

58

Blocked sump strainer

17

Broken fuel injection pump

38

Bad/defective oil temperature switch

59

Broken valve spring

 

drive

 

 

 

 

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

 

 

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