Section 6 - Engine; Engine Troubleshooting - Ariens ST T8 Service Manual

6.1 ENGINE TROUBLESHOOTING

The following troubleshooting chart is to be used to
isolate engine problems and give possible causes and
corrective action responses.
TROUBLE
Black Exhaust
Blue/White Exhaust
Difficult Starting
Erratic Running
Excessive Fuel Consumption
High Oil Pressure
Knocking
Loss of Power or System
Low Cranking Power
Low Oil Pressure
Misfiring
Overheating
Poor Compression
Starts and Stops
Vibration
Will Not Crank
Will Not Start
1 Restriction in air cleaner
2 Bad electrical connection
3 Faulty starter motor
4 Incorrect grade of lubricating oil 25
5 Low cranking speed
6 Fuel tank empty
7 Controls not in correct
operation position
8 Blocked fuel feed line
9 Faulty fuel lift pump
10 Choked fuel filter
11 Battery capacity low
12 Air in fuel system
13 Faulty fuel injection pump
14 Faulty fuel injectors or incorrect
type
15 Incorrect use of cold start
equipment
16 Faulty cold start equipment
17 Broken fuel injection pump
drive
18 Incorrect fuel pump timing
19 Incorrect valve timing
20 Poor compression
21 Blocked fuel tank vent

SECTION 6 - ENGINE

POSSIBLE CAUSES
(Refer to Key Below)
1, 20, 22, 25, 29, 31, 32, 33
4, 20, 25, 31, 33, 34
1, 5, 7, 8, 9, 10, 20, 21, 22, 29, 31, 32, 33
1, 7, 8, 9, 10, 20, 21, 23, 26, 29, 33, 59, 62
1, 20, 22, 23, 25, 39, 31, 32, 33
4, 41
22, 26, 29, 31, 33, 36, 46, 59
1, 8, 10, 20, 21, 22, 23, 25, 26, 31, 32, 33
2, 3, 4, 11
4, 36, 37, 39
10, 20, 25, 26, 28, 29, 32
1, 19, 25,
25, 28, 29, 31, 32, 33, 34,59,
1, 6, 10, 62
20, 23, 25, 26, 29, 33, 45, 49
2, 11, 45
1, 10, 62
TROUBLESHOOTING KEY
22 Incorrect grade of fuel
23 Sticking throttle/restricted movement
24 Exhaust pipe restriction
Leaking cylinder head gasket
26 Overheating
27 Cold running
28 Incorrect tappet adjustment
29 Sticking valves
30 Incorrect high pressure pipes
31 Worn cylinder bores
32 Pitted valves and seats
33 Broken, worn or sticking piston ring(s) 54
34 Worn valve stems and guides
35 Restriction in air cleaner
36 Worn or damaged bearings
37 Insufficient oil in sump
38 Bad/defective oil temperature switch
39 Oil pump worn
40 Pressure relief valve sticking open
41 Pressure relief valve sticking closed
42 Broken relief valve spring
6 - 25
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.
43
44
45
46
47
48
49
50
51
52
53
55
56
57
58
59
60
61
62
CORRECTIVE ACTION
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
repair or replace
see electrical systems
see engine service manual
repair or replace
charge battery or replace
repair or replace
see electrical systems
see engine service manual
Faulty suction pipe
Choked oil filter
Bad solenoid switch
Incorrect piston height
Damaged fan
Faulty engine mounting
Incorrectly aligned flywheel and/or
flywheel housing
Faulty thermostat
Restriction in water jacket
Loose fan belt
Choked radiator
Faulty water pump
Choked breather pipe
Damaged valve stem oil deflector (if
fitted)
Coolant level too low
Blocked sump strainer
Broken valve spring
Exhaust or vacuum pipe leak
Bad or defective water temperature
switch
Bad spark plug(s)