The big diesel con
Join Date: Aug 2009
Location: United Kingdom
Regarding the VNT gubbins (official terminology), you can't really check a lot apart from making sure the actuating lever is free-moving. The vacuum actuator can be checked but requires a vacuum source- or sensor actuation in FiatECUscan etc. If the pipes are ok/ replaced and the lever is free, you should be ok.
The solenoid can be tested, stripped and cleaned also, but this is not worth doing until everything else is sorted- the solenoid is quite reliable.