Picked up a 2008 Audi A4 2.0 Quattro automatic. I drove it a while with no issues, but now I hear a crackle/rumbling when I decelerate or if I feather the gas to stay at speed. Might be more prevalent coasting down hill. Heat it from the firewall. Likes is near the flex pipe. Flex pipe had a large hole, but I just replaced it. Also replaced the PCV valve and hose, diverter valve by the turbo and the N80 valve.
No check engine light. I can hook up a VAG com if needed. I tried resetting the fueling after the new flex pipe. Crankcase has vacuum. Can feel it when I try to remove the oil cap while running. Runs rough without the oil cap.
It’s had the timing chain done and valves carbon cleaned.
u/Emotional_Fix_6605 — 7 days ago