engine management light issues

[ninjab]

A3 1.8T Sport 51 reg. I have the afore mentioned model which a few weeks ago the above mentioned dashboard warning light came on, i did not waste any time and took it to my local garage for diagnostic testing . It came up with three faults 1. turbo valve sensor . 2. throttle body . 3 coolant sensor. The turbo sensor was replaced and after approximateley 100 miles the light came back on , again i took it back and the test meter showed the same three faults , they reported back to me that they had been testing various things ie lambda sensor was slightly down on co2 but not signifiacant to effect the running of my car. I have now done a further 100 miles and the light has come on but the running of the engine appears to be ok , should i be taking this to an audi specialist or has any body got any info as to what would cause this to keep happening .

 

[h100vw]

Go to a specialist mate. I am sure the local guys are good but a specialist would be better.

What would help is having the actual codes they found.

Coolant temp sensors fail all the time. New ones are cheap and easy to fit.

Turbo valve sensor, that could be the N75 maybe which the ECU controls boost with. Thing is a split pipe/boost leak which the ECU can see but will wrongly diagnose can be a tough one to find.

The ECU will measure a difference in pressure between the turbo and inlet manifold. The only thing it can control between the 2 points is the N75. It therefore snags it. It obviously can't find split hoses and slack jubilee clips.

The throttlebody may be out of adaptation, not opening and closing with the throttle pedal, again I would expect a specialist to be more on the case with this kind of thing.

Gavin