Hey everyone, looking for some help on a 2007 A6 3.2l I just picked up. It had a lot of oil leaking from the oil filter housing and the intake variable cam solenoids. I replaced them and when I started the car there was a loud noise that went immediately away so it’s hard to explain and then a rough idle started. You can hear the throttle plate making a sucking noise and I pulled off the intake to see it fluttering open and closed. Got another throttle body from a junk yard and no change.

No check engine light or codes and it got better after driving around. Under acceleration there is no noise or poor performance. I was worried something had gone wrong with the timing chain or tensioners, but would assume there would be a noise along with that, but is it possible something made the chain stretch?

I thought maybe the aftermarket solenoids were to blame so I put the stock ones back in and the idle got worse upon start up again, but then smoothed out to just a slight flutter.

I just have a obd scanner and was looking into getting VCDS or find someone that does but now the obd port is only getting intermittent power and only stays on for seconds at a time. When I bought the car it did have most of the dash lights on (service, wiper, tpms, brake light, airbag. No abs or esc) so I’m reading those might be related but don’t know how to narrow it down.

I have searched all the forums and google for days and have found similar throttle body issues and the things that came up were replace the throttle body or cam solenoids or there could be timing chain issues. Since the tb/solenoids have been replaced, and I haven’t come across any vacuum leaks that leaves the chain. But no codes, no current noises and the fact that it ran fine hours before install leave me perplexed. Until I figure out the obd port does anyone have any thoughts on the throttle flutter? Thank you so much!