vacume leaks ruled out why does a slurpping gurgleing sound come from what seems like the pass side under dash?

 

You didn't exactly give much detail to work with... Try again... Like, under what conditions do your hear the sound?

That said, check condensate drain for clogging.

Steve

 

sorry if i didnt say this. this is my 94 5.8 eng. The sound is made while the ac is on and mostly heard at first start up.. There is also the issue of the vents moving to defrost. I have checked for vacume leaks and can not find any. the diaphram under the dash will close at first but shortly opens back up. Coult moisture have gotten into the system aggravating the vents movement or the vacume thereof.