hillpc

There's a good bit of discussion on the later (2000+) D2 changeover mechanisms that have two sets of flaps to make 3 different runner lengths. But I haven't been able to find much about the 97-99 devices (on the 32 valve engines). I'm not even sure it uses flaps. The Bentley doesn't seem to have much in it about the mechanism. It does talk about the solenoid valve, N156, which, at over 4200 rpm, applies vacuum to actuate the diaphragm. The diaphragm pulls on an arm to actuate the mechanism inside the manifold, making the runners shorter for more horsepower.

I can pull my diaphragm in with a hand vacuum pump (and in and out by hand), so it's not frozen. But it doesn't move back, at least not all the way, when I release the vacuum from the diaphragm. What's supposed to make it go back when N156 shuts off the vacuum to the diaphragm? Would I create any problems by unscrewing the front bolt around which the mechanism seems to rotate so I can try to get some WD-40 in there? (The later 3-stage version supposedly has an internal piece that can drop out of a hole if the input mechanism is unscrewed.)

audinutt

Here's from the SSP 161

hillpc

Thanks! Where'd you get the English version?

audinutt

https://forums.quattroworld.com/a8/msgs/97783.phtml