Mitsubishi S4Q2 User Manual

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Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
ENGLISH
CAUSES OF ENGINE PROBLEMS AND
REMEDIES TROUBLESHOOTING
(• Refer to the separate troubleshooting chart.)
Problems/Symptoms
Hard starting
Glow plugs do not produce red heat Glow plugs do produce red heat to fast
Not enough
power
Exhaust
smoke
abnormal
Engine produces loud knocking sound Engine produces abnormal noice Engine produces irregular combustion sound
Engine
hunts
Engine turns
Cranking speed low
Engine
does
not turn
Small amount of exhaust smoke Large amount of white exhaust smoke Large amount of black exhaust smoke At idling
In
operation
At idling In operation
Possible causes
No exhaust smoke Small amount of exhaust smoke Large amount of exhaust smoke Engine can be cranked manually Engine can not be cranked manually White Black
Air intake system
Insufficient intake air __ __ ⊗ __ __ __ __ __ __ __ ⊗ __ __ ⊗ __ __ __ __ __
Insufficient compression
pressure
__ __ ⊗ __ __ __ __ __ __ ⊗⊗⊗⊗⊗⊗__ ⊗⊗⊗
Ambient temperature is too
high, or ambient pressure is
too low (high altitude)
__ __ __ __ __ __ __ __ __ __ ⊗ __ __ ⊗ __ __ __ __ __
Cooling system
Engine is too cold
__ __ ⊗⊗__ __ __ __ __ __ __ ⊗ __ __ ⊗ __ __ __ __
Excessive cooling by radiator __ __ __ __ __ __ __ __ __ ⊗ __ ⊗⊗__ ⊗ __ __ __ __
Insufficient coolant __ __ __ __ __ __ __ __ __ __ ⊗ __ __ ⊗ __ __ __ __ __
Excessive cooling by radiator __ __ __ __ __ __ __ __ __ __ ⊗ __ __ ⊗ __ __ __ __ __
Water leakage from cylinder
head gasket
__ __ __ __ __ __ __ __ __ ⊗ __ ⊗⊗__ __ __ ⊗ __ __
Cracks in crankcase water
jacket
__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Electrical system
Starter switch defective
__ __ __ __ ⊗ __ ⊗ __ __ __ __ __ __ __ __ __ __ __ __
Starter magnetic switch
defective
__ __ __ __ ⊗ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Starter defective __ __ __ ⊗⊗__ __ __ __ __ __ __ __ __ __ __ __ __ __
Starter free wheel defective
__ __ __ ⊗⊗__ __ __ __ __ __ __ __ __ __ __ __ __ __
Flywheel ring gear and pinion
defective
__ __ __ __ ⊗ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Battery voltage is too low
__ __ ⊗⊗⊗__ ⊗ __ __ __ __ __ __ __ __ __ __ __ __
Open circuit in glow plug or
pilot lamp
__ __ ⊗ __ __ __ ⊗ __ __ __ __ __ __ __ __ __ __ __ __
Short circuit in glow plug
__ __ ⊗ __ __ __ __ ⊗ __ __ __ __ __ __ __ __ __ __ __
Alternator malfunction __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Relay defective __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Wiring defective __ __ ⊗⊗⊗__ __ ⊗ __ __ __ __ __ __ __ __ __ __ __

Mitsubishi S4Q2 Specifications

General

Brand	Mitsubishi
Model	S4Q2
Category	Engine
Language	English