I am having a vacuum noise in my 2008 GP. As soon as the car starts up you can hear it, if you rev the engine the pitch of the vacuum noise goes up. It sounds like a small leak, but no idea where it is coming from... Is there any vacuum lines in the dash or around them in the 2006-2008 range of GP's? I know the older ones had vacuum lines for accessories like the HVAC system... but I can't find any vacuum diagrams for this model date range... I tried some simple checks like disconnecting the brake booster and blocking that vacuum since it was the closest thing to that area... noise still persisted. I hear no vacuum noises under the hood, it's only inside the cabin around the dash. I don't think it's from the HVAC system air flow because I get this noise when the blower is completely off also. Any ideas? Anything to look at?