6
ENGINE DIAGNOSIS
6-1
SECTION 6
ENGINE DIAGNOSIS
CONTENTS
Precaution in Diagnosing Troubles
GENERAL INFORMATION
STATEMENT ON CLEANLINESS AND CARE
An automobile engine is a combination of many machined, honed, polished and lapped surfaces with tolerances
that are measured in the thousands of an millimeter (ten thousands of inch). Accordingly, when any internal engine
parts are serviced, care and cleanliness are important. Throughout this section, it should be understood that proper
cleaning and protection of machined surfaces and friction areas is part of the repair procedure. This is considered
standard shop practice even if not specifically stated.
A liberal coating of engine oil should be applied to friction areas during assembly to protect and lubricate the
surfaces on initial operation.
Whenever valve train components, pistons, piston rings, connecting rods, rod bearings, and crankshaft journal
bearings are removed for service, they should be retained in order. At the time of installation, they should be
installed in the same locations and with the same mating surfaces as when removed.
Battery cables should be disconnected before any major work is performed on the engine. Failure to disconnect
cables may result in damage to wire harness or other electrical parts.