I have the same model AirDog II. I hear mine whine when I stand outside my truck. I checked all connections and found no issues of fuel delivery to and from the pump. I read here in the forums about noise dampening with rubber between the framerail of the truck and the mount. I haven't tried it yet. I did try this with my Viair air compressor, and what a difference it made in the sound and vibration inside the cab. The pump does generate some noise, but compaired to other pumps out there, it isn't as noisy. I run a fuel pressure guage in the feed line to the CP3 and see 20psi all the time. Also, Fleetguard makes the filters to fit this unit. FF 5613, a 2 micron fuel filter and FS 19768, the primary filter and water seperator. Both Dog House Diesel and Diesel Manor sell these online. I changed both filters after 9000 miles, just to check, the 2 micron unit was clean as could be, with the primary filter doing what appears to be most of the work, it had grunge inside. I also drain the water seperator every few tankfulls, twice it had a small amount of water in it. For my piece of mind, I always carry a spare for both filters under my back seat and a filter wrench to remove them in case of an emergency. I too have noticed an improvement in noise reduction, power and economy.