Since the day I picked up my Jeep I've had a very noticable but intermittent growling noise comming from under the dash on the passenger side. My first thought was the heater core or something to do with the cooling system given the location of the noise. The dealership is no help since it's impossible to know when it's going to happen. It happens once or twice a week and lasts for only a few seconds each time. If I had to describe the noise I'd say it sounds like water under preasure that's being released some how giving off a deep growling or gurgling noise. Has anyone else here experienced this? I don't think it's serious but it's getting on my nerves. Any suggestions would be greatly appreciated.