Air cleaner, exhaust gas turbocharger,  OM617

Checking boost pressure of turbocharger

 

 

09—425 Checking boost pressure of turbocharger

 

Test value

 

Boost pressure at full-load, driving
range position ,,L” or ,,S” and n = 4000/min
0.7-0.8 bar gauge pressure

 

Special tool

 

fY-i

 

Tester 0—1.6 bar gauge pressure
617 589 02 21 00

 

j
-£& no

 

Conventional tester

 

Digital tester (or revolution counter installed in vehicle)
e.g. Bosch, MOT 001.03

 

Checking
om617 - 0308-1.jpg
A. On boost air pipe
Connect boost pressure tester to intake manifold, unscrewing plug for this purpose.
Note: Tester connecting thread M 10 x 1.

 

B. On switchover valve
om617 - 0308-2.jpg
Connect boost air tester to switchover valve with Y-distributor, output of switchover valve.
1     Pressure line to boost air pipe
2   Switchover valve
3    Pressure line to ALDA capsule

 

09.8-425/1 F 3

 

 

 

1   Test on dynamometer.
Drive vehicle in driving range ,,S” at full-load and n = 4000/min. The prescribed boost pressure must be obtained.
Check the trouble-shooting hints if system fails to reach specified boost pressure.
2   Road test.
Note: The full-load test must be kept as short as possible because the total driving energy has to be absorbed by the vehicle’s own brakes.
Road-test the vehicle in driving range ,,L” or ,,S” at full-load and n = 4000/min, placing tester in vehicle interior for this purpose. Accelerate to full throttle while holding at 4000/min with the aid of service brakes (No. 2 in illustration). The prescribed boost pressure must be reached.
Check the trouble-shooting hints if system fails to reach specified boost pressure.
om617 - 0309-1.jpg

 

om617 - 0309-2.jpg

 

Compressor inlet (fresh air) Compressor outlet (pre-compressed air)
Exhaust gases toward turbine wheel Exhaust gas outlet

 

Function diagram
2 Compressor wheel                         11
7    Turbine wheel                                14
8    Boost pressure control valve         15
9    Connecting hose                            20 10 Exhaust manifold                          21
Boost air pipe                                           a
ALDA-capsule                                           b
Pressure line                                              c
Pressure switch boost air pipe Switchover valve overload protection
Fuse terminal 15
Switching unit overload protection
Exhaust gas toward bypass duct

 

09.8-425/2 F 3