Tdi deisel engine loses power intermittantly & engine light comes on at same time-diagnostics says engine overboost-What could this be & will it be expensive to fix-thinking it could be some sort of sensor
Friday, November 9th, 2012 AT 3:41 AM
The turbo vanes are stuck and need to be freed-up.
The vanes are vacuum controlled. Vacuum applied = more boost, no vacuum applied = less boost.
Carbon deposits build-up around the vanes and restrict their movement.
Here's a video of me working the vanes back & forth to free them up.
Friday, November 9th, 2012 AT 5:25 AM
Which TDi engine do you have? ALH or BEW?
There are differences in design & control. I'm assuming yours is an ALH.
I presume that you are referring to the waste gate? I was curious so I had a look at your video, it looks like the waste gate control you are freeing up, is this so?
Friday, November 9th, 2012 AT 6:26 AM
Actually not a wastegate... a wastgate dumps exhaust before the turbine so that the turbine does not spool-up or stops
The Variable Vane Turbo uses an actuator rod / pod that repositions the vanes ahead of the turbine wheel... a narrow
passage through the vanes causes quicker exhaust flow to hit the turbine... spread apart vanes cause the exhaust to
hit the vanes at a slower speed.