34
Condition test
Compression test
Special tools:
(999) 8009 Adapter
9691 Compression gauge
1.
Run the engine warm.
2.
Stop the engine and let the mechanical stop control
remain pulled out.
3.
Remove all the injectors.
4.
Fit adaptor 8009. Use the injector retainer to hold
the adaptor in position.
5.
Connect compression gauge 9691 to the adapter.
6.
Read-off the compression gauge at normal starter
motor speed (3.7 r/s). Pressure should be:
DH10A 245, 285 ....................... 3.6 MPa (36 kp/cm
2
)
DH10A 345, 350, 360 ............... 3.2 MPa (32 kp/cm
2
)
8009
9691
10
1
2
3
4
5
6
7
8
7250 Leonberg
M
15
MADE IN GERMANY
25
35
20
30
40
Dat. - - - - - - - -
No.
Kompression in bar
Compression value in bar
Pression en bar
Zyl.
DBGM
Best. Nr. 5 1341 250 00
OTO
M
ETER
A compression test is a simple and reliable way of
finding out the condition of the engine. The test
shows whether or not cylinders and valves are leak-
ing.
Low compression pressure on all cylinders indicate
worn cylinder liners and/or piston rings. Should a
particular cylinder have a lower pressure, this may
be due to leaking valves, broken piston rings or
damaged cylinder head gasket.
Low charge pressure and fuel system malfunc-
tion can cause the following symptoms: low start
torque, and smoky exhaust gases.
Low oil pressure may indicate worn crankshaft
bearings. However, it would be best first to check
the lubricating system valves.
The cooling system is checked for leakage by
pressure-testing the coolant remaining in the sys-
tem. This means that all the following compo-
nents in the system are check for leakage: radi-
ator, connections, hoses, coolant pump, heating
system, etc. See chapter Cooling system.
Camshaft wear can be checked by measuring the
camshaft lift (valve lift) without having to remove
the camshaft from the engine.
The timing gears and camshaft can be checked
by measuring the valve timing. If the valve stroke
deviates from that specified, there is risk of the
exhaust valve striking its piston.
