My 1999 5V V6 Quattro sometimes emits screams of agony from under my dash - like a cat being tortured.
This appears to be a vacuum leak from a broken component, because it sometimes happens AFTER the car has been turned off. Also, the idle dips to about half speed and sometimes the engine dies when this happens. Also, there is a sort of rushing of air sound just before the scream starts.
This appears to be something to do with the HVAC system, because turning it off stops the problem.
Other possible clues: There is little heat, and the Cruise Control doesn't work.
However, the HVAC diagrams I have found do NOT seem to include any vacuum driven components.
So, what vacuum-driven components of the HVAC system are there to break down, where are they located, and how can I get to them?
Any help will be GREATLY appreciated.
Steve Richfield