I am in Sedona and can't get under the bus but I hear a consistent noises between the drive axle while parked that sounds like a fog "beacon on the coast" is very low pitch and last about a second and goes off regularly around every 15 seconds. I have a compressor running to keep my aux air up so I don't dump the tags. I know I have one more 5 port Norgren to replace after this trip. Any ideas what this noises is from?