Could i have put my turbo together incorrectly

[osullivant]

I am having continuing issues with Airflow through engine. This is a very much a stab in the dark but I have the sense that the volume of air being drawn into the engine at low revs is incorrect.

Unless I am wrong,,,,,,, quantity of airflow is contributed to by the Turbo which is driven by exhaust, whilst the speed at which the turbo is driven is influenced by the position of the vanes in the Turbo. and thus the positioning of these vanes directly influences the quantity of air drawn into the engine.

When I was reassembling the turbo could I have put these vanes back incorrectly, so that they were out of sync with the lever which operates them thus, only at midpoint would they be close to their correct position.

I say this because the car is beautiful to drive at about 2500rpm in 6th at 120kms which is pretty close to mid ways...

can this be diagnosed using VIDA.....

Any advice or info Please!!!!!

Tony.

[moorgate]

Loss of boost at the RPM you describe is more likely to be a loss of *vacuum* - the vanes are sucked into the high revs position by the turbo control system. hunt vacuum leaks!

[cheshired5]

Originally Posted by moorgate

Loss of boost at the RPM you describe is more likely to be a loss of *vacuum* - the vanes are sucked into the high revs position by the turbo control system. hunt vacuum leaks!

If your D5 turbo is actuated by an electric motor, a vacuum leak hunt will be a wild goose chase.



OP, yes the turbo can be actuated by Vida and you can watch the arm movement to see if it's adjusting correctly.

[osullivant]

Originally Posted by cheshired5

If your D5 turbo is actuated by an electric motor, a vacuum leak hunt will be a wild goose chase.



OP, yes the turbo can be actuated by Vida and you can watch the arm movement to see if it's adjusting correctly.

Yes it is an electric motor so no vacum issue, and yes vida moves the actuator but I am concerned that I put the Turbo together incorrectly so that the vanes are in the wrong position at idle.

looking at the turbo sites and http://www.turbodynamics.co.uk/downl...rbocharger.pdf

In particular it could well be an issue, I have been going through all the work I did and this is really the only piece that I interfered with that could have such a long lasting and consistent, non obvious fault. sods law also dictates that the problem will be simple but the hardest possible to get at ....

[osullivant]

Disconnected the connection to the actuator whilst the car was switched off.

Started engine cleared all codes and went for spin, car permanently in Limp mode but driving smoothly just driving as if I had a heavy trailer on the back. and certainly the first trip that did not finish with a Maf 135f fault

Unless there is another way to diagnose or rule out the possibility of incorrect assembly, I am going to have to get very very dirty again.

Does anyone have good images that show the CORRECT positions of the vanes when the turbo is being assembled.

thanks for all the help todate.....

[RM955I]

Not wishing to teach you to suck eggs but I always understood that if a turbo was disassembled, it needed professionally balancing. That may not be your issue but perhaps worth mentioning.

[5cilinder]

The electric vnt can be callibrated in vida if im not mistaken

[RM955I]

I doubt VIDA can carry out physical balancing of the vanes.

[5cilinder]

Who said the vanes are in I(im)balance? He got limpmode by incorrect pressure /airflow
If the refference/start position of the vnt is not callibrated it can overcompensate with all the symptomes wich are mentioned

An imbalanced turbo can work perfectly without limpmode until it breaks

[RM955I]

Originally Posted by 5cilinder

Who said the vanes are in I(im)balance

Sigh.....

Who says the vanes are balanced? My point is that (a) If the turbo has been dismantled it may need balancing and (b) not everything can be fixed by a piece of software.

I am not now, and never did, state that his problem was solely caused by an out of balance turbo: just that it was a consideration.