Bouncing idle
 

Please let me know if there is already a thread about this, but i searched and could not find one. So here is my problem, when the car is idling and i barely touch the throttle and hold it (the amount of throttle isnt being changed) the revs seem to bounce. Had this problem before and changed the ignition coils as it was also throwing misfire codes before and now it is just doing this. Any ideas?

here is a clip of the Tach showing the rising and falling revs
http://www.youtube.com/watch?v=Wj4msshLIdQ

Check for vaccum leaks. There is a breather hose that runs on top/front by the coil pack/ignitor where the wires plug into (you have a 2.8, right?) that is known to crack and leak. It definitely looks like a vac leak, but try cleaning your throtle plate and do a TBA if you can.

Thank you and yes it is a 2.8. I just checked the vaccum hoses and found one not on the corrigated plastic but on a braided plastic hose that is connected to the "fuel pipe" (part number 078133681aj). What are the consuquences if i were to drive it with a taped up leak for a week or two?

spend the couple bucks and replace the hose ASAP

Just ran down to the shop and bought all new hosing. As long as i have not missed a hose they are all new. The problem is a persistant bugger.

If it's the corrugated PCV hose, it's not a "couple bucks" it's about $90. You can easily tape wrap it. It does sound like a vac leak but try the TBA and see what happens - that can definitely help.

$90 bucks for a plastic hose

WTF?

No joke. That was $89.xx from ECS last year. It's why my cracked one is taped up instead of replaced.

do you have a link or part number for that hose?

Looks like it came down some. Now it's only $74 lol.

http://www.ecstuning.com/Audi-B5_A4-...ission/ES3224/