mjohanson.08

My 1997 A4 is running great with one small problem. When i put the car into Neutral coming to a stop the rpm's jump from about 1100(idle) to 2000, and back and forth. It starts at about 30 mph and doesnt happen before then. However when i stop the car completely, the jumping stops and the car idles normally. Anyone have any ideas?

spoiledA4

ya, here is an idea. That sounds exactly like there is a boost leak. With a boost leak, the car has enough air for the gas so it brings the rpm up, and then down when the boost gets too much for the leak. When you idle there is very little boost, maybe 1 psi and the car can idle correctly. Check your hoses and intercooler. If not that, you may need to check some gaskets. Get back to me if you find out what it is, good stuff to know.