Hi,

I have a 2004 cabriolet quattro 3.0l, CVT, 44,000 mi. I just replaced all of the coils and had major service.

I have noticed that when I stop at a stoplight, the car vibrates and it feels like the transmission is engaged and the car is trying to go forward (but it can't, since I have the brakes on). The idle speed is around 800 rpm. The vibration goes away if I put the car into park or neutral, which I now do at most stoplights. If I let up on the brake, and the car is idling in gear, then it starts to move forward at about 3-5 mph on level ground. I guess this is similar to another post.

I asked my mechanic about it. He claimed that it is a 'problem with the pcv valve'; he opened the hood and opened the oil filler cap, and put his hand over the oil filler hole; you could feel a lot of air pressure pushing out of the oil reservoir.

It seems to me that these cars do not have a pcv valve, but there is some sort of crankcase ventilation system.

Does anyone know much about how to diagnose this kind of problem, or should I let the mechanic do it?

Bruce