6
N73B60 Engine - Diagnosis
Intake Manifold
The intake system is a complete component constructed of magnesium in a shell type
design and has separate manifold chambers for each cylinder bank.
1. Intake manifold pressure sensors
2. Captured gaskets
3. Pressure control valves for crankcase
ventilation
4. Throttle valves
The individual parts of the intake system are bonded and bolted to each other, providing
considerable weight reduction (separating the shell halves is not permitted).
The entire intake system is protected against corrosion by a dip coating procedure. The
fastening bolts of the add on parts are also coated and must be replaced in the event of
damage, to prevent corrosion and pitting.
All of the gaskets (2) are secured by retainers (captured) to provide ease of installation. The
intake system is isolated from the engine by rubber elements on the fastening bolts.
An intake manifold pressure sensor (1) is used for each cylinder bank. Recording the man-
ifold differential pressure is necessary for the correct throttle position (synchronization) so
that a manifold differential pressure of 50 mbar can be balanced on each bank.
Both sides of the induction system are fitted with a pressure control valve (3) for crankcase
ventilation which is distributed to both banks.
N
No
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e::
When replacing the spark plugs, it is necessary to remove the entire intake system to
avoid damaging the spark plugs during installation. The spark plugs must be replaced
every 100,000 miles in US vehicles.
KT-9589
