[Saurian]

My jeep has wheels... :?

Seriously, while I have no idea of that last bit, I do know that a vacuum leak is quite audible... My suggestion, therefore, is that perhaps something is clogged... Are all your vacuum actuated systems working OK... I know that a biggie is the HVAC; if you have it set to vent, and it's only going floor/defrost, there's a vacuum problem, because those doors are all vacuum actuated...

Just a suggestion, that's all I've got. I'd kill for just a nice simple vacuum leak right about now...