2004 BMW 745i Base 8 Cyl 4.4L
When I start my car from a cold state it makes a vacuum sound for about 45 sec then go away. When I stop at the stop li
Car has 104000. Codes are PO491 and PO492
You have a air injection air supply hose under intake manifold that is broken and leaking and this is your noise that you hear and this is the two codes you are getting. the secondary air pump puts out air pressure that is escaping from the broken air supply hose. The intake manifold has to come off and the part is a dealer only part.