2005 Civic EX SI sounds like a monster truck
 

Hello All,
I just hit 90,000 yesterday and noticed on the way back home when letting off the gas pedal I heard what sounds like the you would hear from a large 4x4 with heavy mud/snow tires, tire hum, yes tire hum. Just a steady hum as the car slows, both coasting and when braking. Thought it could not be the car and must have run over some tread marks on the road left by a dozer or something. Next time I slow down on the highway there it is again. Later that day with wife and son in the car, they hear it too so was not just me. So 24 hrs later it is still there each time you coast/brake. Never heard it before until yesterday. To best describe the sound is like that tire hum you would hear on big tires you see on 4x4's. Or, that prop sound you would hear inside the cabin of a twin prop airplane. Not extremely loud but most definitely able to hear it. Ideas? Suggestions? It is 90K, tires replaced at 87K, brakes replaced at 47K.