Checking Charge-Air Pressure - Man D 2866 LUE 605 Repair Manual

Sufficient boost pressure is essential to ensuring full power output and clean combustion.
Checking the boost pressure helps to detect damage to the turbocharger and leaks in the intercooler and in
the charge-air pipes.
Extreme operating conditions (full-load operation and high air temperature) and the use of unsuitable en-
gine oils (see also publication "Fuels, Lubricants and Coolants for MAN Diesel Engines") may give rise to
deposits on the compressor and in the intercooler, resulting in a reduction in boost pressure.
Preconditions for measurement
The start of fuel delivery and valve clearance must be set as specified and the engine must be at normal
operating temperature.
Charge-air pressuer:
No generally applicable target value for charging pressure can be given, as the installation conditions exert
an influence.
The target value is the value determined on commissioning of the engine and reported in the commissio-
ning log.
Specific instructions during measurement
Based on various atmospheric reference conditions during the measurements and on tolerances of the
pressure gauges used, deviations of max. $100 hPa ($100 mbar) are permitted.
Fig. 1
The measuring connection for checking the
charge-air pressure and the charge-air tempera-
ture is located in the intake pipe at the point where
the flame-starter sheathed-element glow plug is
screwed in.
Remove flame-starter sheathed-element glow plug
see page 38.
Manometer (eventuell mit Hilfe eines passenden
Gewindestutzens als Adapter) anschließen.
Fig. 2
Measure the boost pressure downstream of the
intercooler at rated engine speed and full load.

Checking charge-air pressure

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