Possible symptoms due to starting system trouble would be as follows:
Starting motor does not run (or runs slowly)
Starting motor runs but fails to crank engine
Abnormal noise is heard
Proper diagnosis must be made to determine exactly where the cause of each trouble lies.....in battery, wiring harness, (including starting motor switch), starting motor control relay (for K9K Engine), starting motor or engine.
Do not remove motor just because starting motor does not run. Check the following items and narrow down scope of possible causes.
1) Condition of trouble
2) Tightness of battery terminals (including ground cable connection on engine side) and starting motor terminals
3) Discharge of battery
4) Mounting of starting motor
For K9K Engine
Condition Possible Cause Action
Abnormally worn bush
Replace starting motor.
Worn pinion or worn teeth of ring gear
Replace starting motor or flywheel.
Poor sliding of pinion (failure in return movement)
Replace starting motor.
Worn internal or planetary gear teeth
Replace starting motor.
Lack of oil in each part
Replace starting motor.