Why wouldn't my turbo charger kick in? (Vito van110 CDI)

Question

Why wouldn't my turbo charger kick in? (Vito van110 CDI)

Answer 1

Pressure test the system and see if there is a boost leak somewhere.  

Answer 2

what is your intake manifold pressure with the gas down at higher than 4000rpm ?

do you have an intake manifold pressure gauge ? it may be a good thing to have if you don't.

Answer 3

The Vito 110 CDI is known for this problem. Strangely the 109 isn't affected.

Answer 4

Some vans only kick in after 4500 rpm

Answer 5

Hi a turbo is just a mechanical fan/compressor blade mounted on a shaft which is driven by a paddle wheel on the other end witch is driven by the exiting exhaust gasses,the pressure inside the turbo casing is controlled by a waste gate or dump valve if either of these  types of pressure relief valve are stuck in the open position then no pressure/boost will build.It is possible for the turbo to seize (blocked oil feed) so check that the turbo will rotate freely by hand,most turbocharged engines use a inter cooler to cool the intake air and increase it's density this is basically another radiator but if a leak appears the boost pressure may be lost most air leaks can be heard as a high pitched whistle.Also there is usually a pipe from the turbo to the fuel pump or ecu on common rails to let it know what pressure the turbo is producing if this is blocked or missing it may well not allow the correct diesel to be injected...