After posting a few days ago and not getting any response. I have discovered a new puzzling symptom with my Audi. When I remove the oil filler cap there is a large vacuum and the rpms go up and stabilize around 800 rpms. Put the cap back on and the car will start to lope and die. Has anyone ever heard of this? Below is my original post:


I just purchased a A6 quattro avant 3.0 v6 awd for my wife to drive. It was missing when I purchased it. Scan showed misfire on 2,3, and 6. Replaced coil packs and plugs, no change. Replaced crank case vent valve (diaphragm was cracked), no change. Injectors appear to be working and test at 13 ohms. At idle the rpms will pulse between 600 to 1200, and after a while it will die. Really need help to figure this out. The car is in really good condition and I can not afford to take to a mechanic right now.