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Fig. 2: Identifying Variable Intake Manifold - Shown On Engine 113
INTAKE MANIFOLD, FUNC TION - GF09.20-P-3102-02A
Engine 112, 113
Section through variable intake manifold in cylinder plane
Fig. 3: Identifying Intake Manifold Function
- Section Through Variable Intake Manifold In Cylinder
Plane
When the engine is started and at low engine speeds the variable flaps are open. The intake air flows along the
shortest path and thus reaches the cylinder with low friction losses from the distributor volume.
At an en
gine load of more than 50% from approx. 1750 rp m up to approx. 3900 rpm the variable flaps are
2001 Mercedes-Benz ML320
1998-2005 ENGINE Air Intake, Turbo Charging - 163 Chassis
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Page 1154 of 4133

closed. The intake air must flow through the whole intake pipe. Its length is selected in such a way that the
pressure waves, produced by the inducting pistons, arrive at the right moment at the open intake valves for the
next induction stroke. The result is improved cylinder charge and thus an increase in torque.
At higher engine speeds (e.g. from 3900 rpm) the actuation to the variable intake manifold switchover valve is
interrupted - the variable flaps open as a result of the spring force. Through the shortened route the pressure
waves arrive in time even at higher rotational speeds before the closing of the intake valves to the combustion
chamber.
INTAKE MANIFOLD, DESIGN - GF09.20-P-3102-03A
Shown on ENGINE 112
Fig. 4: Identifying Intake Manifold Components
- Shown On Engine 112
The intake manifold is assembled out of several magnesium pressure castings. When fitted together, they
produce the individual intake manifolds and the air collecting volume. The parts are sealed off to each other by
plastic. The intake manifold cannot be disassembled.
The individual intake manifolds each approx. 800 mm long, are arranged in a spiral shape around the air
collecting volume. A single intake manifold is assigned to each cylinder.
Each single intake manifold has a further opening to the air collecting volume in the middle. These can be
opened or closed by means of variable flaps which pivot through approx. 60°.
The variable flaps are attached to steel shafts. One shaft is installed for each bank of c
ylinders. The
2001 Mercedes-Benz ML320
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Page 1155 of 4133

interconnected flap shafts are closed by means of vacuum by the intake manifold switchover diaphragm unit.
When the variable intake manifold switchover valve is open, the vacuum is supplied from a vacuum reservoir
with check valve in the intake manifold. The reservoir volume is designed for about 5 operations without
renewed evacuation.
The variable flaps open by means of spring force.
INTAKE MANIFOLD, LOCATION/TASK/DESIGN/FUNCTION - GF09.20-P-3102A
ENGINE
112.910 /911 /912 /913 /914 /916 /917 /920 /921 /922 /923 /940 /941 /942 /943 /944 /946 /947 /949 /953 /954 /9
5
ENGINE 113.940 /941 /942 /943 /948 /960 /961 /963 /965 /967 /966 /968 /969
Fig. 5: Identifying Intake Manifold Design/Function
Intake manifold,
location GF09.20-P-3102-
01A
Intake manifold, taskOptimizing engine torque curve by means of two different
intake manifold lengths
Intake manifold,
design GF09.20-P-3102-
03A
Intake manifold,
function GF09.20-P-3102-
02A
2001 Mercedes-Benz ML320
1998-2005 ENGINE Air Intake, Turbo Charging - 163 Chassis
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Page 1156 of 4133
TESTING & REPAIR
INTAKE MANIFOLD CONNECTION DIAGRAM - AR09.20-P-1310-01A
Connection schema intake manifold Engine 112
Fig. 6: Intake Manifold Connection Diagram
- Connection Schema Intake Manifold - Engine 112
INTAKE MANIFOLD CONNECTION DIAGRAM - AR09.20-P-1310-01AA
Connection diagram of intake manifold engine 112 with USA version code 494a
2001 Mercedes-Benz ML320
1998-2005 ENGINE Air Intake, Turbo Charging - 163 Chassis
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Page 1157 of 4133
Fig. 7: Intake Manifold Connection Diagram - Connection Diagram Of Intake Manifold - Engine 112
With USA Version Code 494a
INTAKE MANIFOLD CONNECTION DIAGRA M - AR09.20-P-1310-01AC
Shown on engine 113 with USA version code 494a
2001 Mercedes-Benz ML320
1998-2005 ENGINE Air Intake, Turbo Charging - 163 Chassis
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Page 1158 of 4133
Fig. 8: Intake Manifold Connection Diagram -Shown On Engine 113 With USA Version Code 494a
INTAKE MANIFOLD CONNECTION DIAGRAM - AR09.20-P-1310-01AU
Shown on engine 113
Fig. 9: Intake Manifold Connection Diagram
- Shown On Engine 113
REMOVE/INSTALL INTAKE MANIFOLD - AR09.20-P-1310A
ENGINE 112.910 in MODEL 202.026/086
ENGINE 112.920 in MODEL 202.029/089
ENGINE 112.921 in MODEL 210.063/081 /263 /281
ENGINE 112.922 in MODEL 220.063/163
ENGINE 112.923 in MODEL 129.059
ENGINE 112.940 in MODEL 208.365/465
ENGINE 112.941 in MODEL 210.065/082/265/282
ENGINE 112.942 in MODEL 163.154
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ENGINE 112.943 in MODEL 129.064
ENGINE 112.944 in MODEL 220.065/165
ENGINE 113.940 in MODEL 210.070/270
ENGINE 113.941 in MODEL 220.070/170
ENGINE 113.960 in MODEL 215.375, 220.075/175
ENGINE 113.961 in MODEL 129.068
ENGINE 113.944 in MODEL 202.033/093
ENGINE 113.942 in MODEL 163.172
ENGINE 113.980 in MODEL 210.074/274
ENGINE 113.943 in MODEL 208.370/470
ENGINE 113.984 in MODEL 208.374
ENGINE 113.981 in MODEL 163.174
ENGINE 112.912 in MODEL 203.061/261, 209.361 /461
ENGINE 112.946 in MODEL 203.064/264
ENGINE 112.947 in MODEL 170.465
ENGINE 113.963 in MODEL 230.475
ENGINE 113.968 in MODEL 209.375/475
ENGINE 112.913 in MODEL 211.061/261
ENGINE 112.949 in MODEL 211.065/265
ENGINE 113.967 in MODEL 211.070/270
ENGINE 113.987 in MODEL 209.376/476
ENGINE 112.955 in MODEL 209.365/465
ENGINE 112.916 in MODEL 203.081/281
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Page 1160 of 4133
ENGINE 112.953 in MODEL 203.084/284
ENGINE 112.970 in MODEL 163.157
ENGINE 112.972 in MODEL 220.067/167
ENGINE 112.973 in MODEL 230.467
ENGINE 113.965 in MODEL 163.175
ENGINE 112.975 in MODEL 220.087/187
ENGINE 113.948 in MODEL 220.083/183
ENGINE 113.966 in MODEL 220.084/184
ENGINE 112.917 in MODEL 211.080/280
ENGINE 112.954 in MODEL 211.082/282
ENGINE 113.969 in MODEL 211.083/283
ENGINE 113.988 in MODEL 203.076/276
ENGINE 113.989 in MODEL 171.473
Shown on engine 112
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