Page 24 - E BOOK ENGINE MECHANICAL M2

4. ENGINE OVERHAUL

1. INTRODUCTION

Imagine that a customer brings in his vehicle and com-
plains about engine problems such as “No power”,
“Black smoke emission”, “Noisy engine”, “Hard to start
engine,” and so forth.
What do you do in these cases? Do you start disas-
sembling the engine instantly in response to what the
customer is saying? Or, do you take sufficient time to
investigate the causes of the troubles on the vehicle be-
fore you decide your course of action?
For instance, imagine that you go to see a doctor be-
cause you are suffering a headache. Would you trust a
doctor who may insists in exploratory surgery to see in-
Fig. 4-1
side of your head without providing enough medical ex-
amination?

2. ENGINE OVERHAUL JUDGMENT

Even if you have plenty of practical experience, we recommend that you conduct some inspections
before you may come to the determination that an engine may require an overhaul. Some clues to
consider in order to find out the trouble cause can be obtained through observation of basic check
items like the ones listed below:
◆ Engine coolant (Level, deterioration)
◆ Engine oil (Level, dirt, viscosity)
◆ Battery (Connections of battery cable, level and
specific gravity of electrolyte)
◆ Air cleaner element (clogged, dirt)
◆ Auxiliary belt (Tension, wear, damage)
◆ Sparkplug (Firing end appearance, sparkplug gap)
◆ Ignition timing and engine speed at idling
◆ Color and smell of exhaust emission (Black, white)
◆ Fuel system (Electronic control system operation,
fuel quantity and quality)
Fig. 4-2 ◆ Abnormal noises, striking sound, knocking
◆ Fuel consumption ratio
◆ Oil consumption ratio
◆ Etc.

4 - 1 Pub. No. PTAE1225