Hi there!
I have owned an A4 2007 with a BRD engine 170hp for several years and have a problem i cant find the answer to. It comes and goes and therefore mechanics cant find the problem when they have the car.
Using OBD tool i have found that it is wierd readings of the throttle position sensor when the engine runs bad.
Here are my observations:
-When the car runs smoothly which is 90 % of the time. Throttle positions sensor is inactive, which means it stays at 4,7% no matter how much i accelerate.
-When the problem is active i have delayed acceleration, not running smoothly on low rpm. Then the throttle position sensor is at 80% when idling. It sounds like a fan is blowing or a vacuum cleaner is inside the engine, like it's sucking air into it. When i then press down the pedal there is a delay in acceleration while TPS drops to 4,7% and i get normal acceleration until i remove my foot from the pedal and it will go back to 80 % and suck for air. When i stop the car and let it idle, it will take about 2 minutes before it goes from 80 % and back to 4,7 %.
I have changed the entire throttle body and EGR without luck. Thinking the problem must be somewhere else.
Have noticed the problem occuring more often during rain and wet roads. Rarely happens when driving at high speed.
Video showing TPS being at 80% and dropping to 4,7% when accelerating. At 5:38 in the video the TPS drops to 4,7% and stays there and when this happens the car runs smoothly again. https://www.youtube.com/watch?v=91OYzBz2BN8&t=402s
Video of the fan sound. At 1:05 in the video the sound disappears and engine is back to normal. https://www.youtube.com/watch?v=JPILhFyy36U
Hope someone can help troubleshoot =)
-Eirik
