How to adjust the variable vane turbo actuator arm?

DEACAT

MEMBER
2006 MERCEDES BENZ VITO
2.2L
4 CYL
2WD
MANUAL
165,000 MILES

2006 115 CDI Vito turbo vane actuator arm adjustment.

So, I've had to adjust the length of my actuator arm on the turbo (long story - sticking vanes), but I stupidly didn't mark where the adjustment was before changing it.
Anyone any ideas on how to set up the length of the arm correctly? Not the kind of thing to just 'guess' and try, is it?

2 Replies

BORIS K

MECHANIC
762 POSTS

Hello,

Unfortunately, the manufacturer does not provide a specific rod length for the VGT actuator.
To adjust it correctly you would require a hand vacuum pump such as a Mightyvac.
See image 1 below

A good video:
https://youtu.be/gYkNMOzsk14

To get the initial adjustment you will need to remove the actuator arm from the VGT linkage, ensure that you catch the circlip.
With the VGT linkage all the way to the lower stop adjusts the arm so that it will slip on.
Next attach the hand vacuum pump to the actuator. Pump the vacuum pump until you get around 18 inches of mercury, 600 mbar of vacuum.
Check if the VGT linkage has touched the upper end stop. see image two below
If not then release the vacuum and shorten the rod, start with around two turns.
Do not adjust the end stop screw!
Next apply the same vacuum again and see if the VGT linkage will reach the end stop.
If it reaches the end stop too soon or still does not reach the end stop, adjust the rod length accordingly.
Please note that the end stop should not be reached with lower amounts of vacuum as this will cause the vehicle to reach its maximum boost too soon and cause an over boost situation.

Hope this helps.

Cheers, Boris

Images (Click to make bigger)