Morning guys, i bought my first audi at the weekend and when i was driving it back i could not believe how much of a nice drive it was even being a high mileage one, one thing that was niggling me though was that from idle, when you apply the throttle it seems to hesitate for a few seconds then rev? i opened the bonnet and did the same, when i did it there was a sharp suck of air from underneath the header tank, any ideas? the car is, 1999 Audi A4 1.8 Est 20v. p.s just behind the header tank is an acctuator looking thing close to the bulkhead, the sucking is coming from near there?

 

um...???

 

it's a vacuum leak.... that is causeing you problem, but i like joen have no clue what parts you are really trying to describe..... i think you are talking about the vac lines all running under the intake manifold, and maybe the bulkhead is the firewall?..... now the actuator you are talking about could be n112 stuff, or purge valve(i think) back by firewall