Testing The Compression Pressure - Mitsubishi S4Q User Manual

GENERAL INSTRUCTIONS
Compression
gage adapter
Figure 1 Measuring compression pressure
Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
TESTING THE COMPRESSION
GENERAL INSTRUCTIONS
4 TESTING THE
COMPRESSION
PRESSURE
Start by:
a. Make sure the engine oil, air cleaner, starter
and battery are normal
b. Start the engine and allow it to warm up
thoroughly
1. Move the stop lever to the stop position.
2. Remove the glow plugs from all cylinder heads.
Connect compression gage (33391-02100) to the
cylinder on which the compression is to be
measured with compression gage adaptor (30691-
21100).
3. Crank the engine with the starter, then read the
compression gage indication while the engine is
running at the specified speed.
4. If the compression pressure is lower than the
repair limit, overhaul the engine.
CAUTION
a. Measure the compression pressure on all
cylinders.
b. Compression pressure varies with the
engine speed. Check the engine speed
when measuring the compression
pressure.
Item
Compression pressure
NOTE
Meaure the compression pressure with the engine
running at 150 to 200 rpm
ENGLISH
PRESSURE
2
Unit: MPa (kgf/cm ) [psi]
Assembly Repair
Standard Limit
2.94 2.55
(30) (26)
[427] [370]
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