Audi A3 1.9 TDi PD - Black smoke under acceleration #
Posted by Mark Robins on November 16, 2009, 9:07 am
Year of Manufacture *: 2005 Engine Code or CC *: 1.9 PD ( Optional ) Scanner Used: Autocom
Audi A3 1.9 PD Tdi 2005
Vehicle emits an excessive spurt of black smoke under acceleration from a cruising speed of around 40 mph upwards, there is also a hesitation when this happens, it then clears and everything is normal. Only fault codes are related to heater plugs 1,2,3,4 which we replaced, EGR valve was inspected and found to be absolutely mucked up as was the inlet manifold, we removed the manifold and cleaned it out and replaced the EGR but this made no difference. If the EGR is disconnected by removing the Vacuum pipe the problem disappears, so we monitored the vacuum supply with a vac gauge to see what was happening. The vacuum seams to be switching on and off quickly until the above mentioned driving condition, from a cruising speed of 40 mph and upwards when the vacuum drops off very slowly before finally getting to down to zero. I suspect the EGR control solenoid but it looks like its housed in a module and I guess pretty expensive. Does anyone have any ideas or has anyone come across this problem before?
Mark Sorry for the long post
Re: Audi A3 1.9 TDi PD - Black smoke under acceleration #
Nope never did get to the bottom of it, but the customer is happy to drive around with the EGR pipe plugged and the MIL on!!! I moniterd the vacuum and I'm convinced that the problem lies with Vac control, whether that be the control solonoids unit or some external control. Let me know how you get on.