Question 2
(a) State one function of each of the following in the starting system of a motor vehicle:
(i) battery;
(ii) flywheel;
(iii) solenoid.
(b) Table 2 contains symptoms of faults in the starting system of a motor vehicle.
Table 2
Symptom of fault |
Possible causes |
Remedies |
Starter motor cranks slowly |
(i) |
(i) |
(ii) |
(ii) |
|
Starter spins but does not crank engine |
(i) |
(i) |
(ii) |
(ii) |
|
Noisy starter motor |
(i) |
(i) |
(ii) |
(ii) |
Complete Table 2 by stating two possible causes and remedies for each symptom.
Observation
(a) (i) The battery supplies d.c. current into the system.
(ii) The flywheel links the pinion to crank the engine.
(iii) The solenoid acts as relay circuit/connects and disconnects the pinion.
(b) Table 2
Symptom of fault |
Possible causes |
Remedies |
Starter motor cranks slowly |
Low battery voltage |
Charge/replace battery |
Loose/corroded/broken connection |
Clean/repair/replace connection/terminals |
|
Cable size too small |
Replace with proper size cable |
|
Internal starter motor problems/faulty starter motor |
Replace/overhaul starter |
|
Engine oil too thick/high viscosity |
Use oil of proper viscosity |
|
Faulty shaft |
Replace shaft |
|
Ignition timing too far advanced |
Set timing to specifications |
|
Starter spins but does not crank engine |
Defective plunger overrunning clutch |
Replace defective part |
Broken starter drive gear |
Replace drive gear |
|
Broken flywheel teeth |
Replace flywheel |
|
Noisy starter motor |
Loose starter mounting |
Tighten mounting bolts |
Worn starter drive gear/flywheel teeth |
Replace starter/flywheel |
|
Worn starter bushing |
Replace/overhaul starter |
|
Excessive vibration |
Replace starter/flywheel |
Candidates were required to state possible causes of the symptoms of faults listed in the Table and their corresponding remedies. Only a few candidates were able to state the matching remedies to causes stated.