Well, I drove approx 120 miles today on the freeway cruise set around 70-75, and at about 60 miles in I start to hear a tapping. It sounded like a flap of tire peeled off and everytime the tire spun it would flap against the fender and make this tap sound. It was steady for around 7 taps, then intermittent, 5 taps, 6 taps, 3 taps. All in a steady time. It was not in time with the rpm or revolutions of the engine nor was it in time with the revolution of the tires. I pulled over and checked all the tires. No problem. Popped the hood and cranked it and no visible or audible sounds during my inspection. When I returned to the road a few minutes later the sound came back the same way. I followed a hunch and turned the ac off. The sound did NOT come back. So now I wonder if my ac could make this tapping sound. It seemed to be coming from either just above the transmission or behind the dash. It wasn't the cupholder. It wasn't the wipers or antenna. No loose items in the cab. Just wondering if anyone has had a similar sound. And have any idea what it could be. Within the last 2k I have done the plugs, rotors, hubs and pads, fuel filter, air filter, MAF and TB. Any help is appreciated. I will repost tomorrow after the drive home. I will experiment more with the ac on and off.

 

Also, my ac was blowing ice cold the whole time.

 

Anyone?