12 / 174
Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
ENGLISH
DETERMINATION OF OVERHAUL TIMING GENERAL INSTRUCTIONS
GENERAL INSTRUCTIONS
3 DETERMINATION OF
OVERHAUL TIMING
In most cases the engine should be overhauled when
the engineís compression pressure is low. Other
factors that indicated the necessity of engine overhaul
are as follows:
1. Decreased power.
2. Increased fuel consumption.
3. Increased engine oil consumption.
4. Increased blow-by gas volume through the
breather due to abrasion at the cylinder liner and
the piston ring.
5. Gas leakage due to poor seating of the inlet and
the exhaust valves.
6. Starting problems.
7. Increased noise from engine parts.
Any one or a combination of these symptoms may
indicate that engine overhaul is required. Of the items
listed above some are not directly related to the
necessity of engine overhaul. Items (2) and (6) are
more likely to be affected substantially by
• Injection volume of the fuel injection pump
• Fuel injection timing
• Wear of injection-pump plunger
• Fitting of the injection nozzle
• Condition of electrical equipment: battery, starter,
or alternator
Item (4) above, however, requires special consideration
because decreased pressure due to wear at the
cylinder liner and the piston ring is one of the most
obvious signs that the engine requires overhauling.
The most effective way to make a decision is by testing
the compression pressure; other factors are to be
considered secondarily.
To Next Page
Loading...
Need help?
General
