Front End Scraping Noise

The past few days I have noticed a scraping noise coming from the front end. I'll provide more details below, but it sounds like spent brake pads scraping against the rotor. I am on vacation 6 hours away from home or I would have already checked this out in further detail. The car has 150k, I've had it for a year and a half with no issues (other than an inverter valve). Tire wear is even and plenty of tread.

Things I Know

• The scraping is consistent with the revolution of the tires
• The sound does not increase when braking or turning
• The sound does not happen when parked and engine running
• The sound happens in neutral and in drive
• No vibration in the floorboard
• The steering wheel is steady
• Car drives straight
• The sound is audible up to ~ 70 mph, depending on road noise
• Rotors look okay, no rust and clean. Worn a bit but I have seen much worse.

Things I've Tried

• Coasting in neutral and applying the friction brakes at ~ 50 mph
  • The friction brakes feel great, plenty of stopping power, no change in sound
• Tight turns at ~ 50 mph do not affect the sound

Things I want to try next

• Check for play in the tires to ensure hub assembly is okay
• Check U-joints, cv joints
• Check brake pads, slides, clips, dust cover
• Not sure if any heat shields are near moving parts, but verify no contact

Is there anything I am missing here, something else I should look for?

 

I am finally back from vacation, and went ahead and ordered new rotors and pads and put them on last night. I could have went a few extra thousand miles but why not replace them while I'm looking at it?

I got the tires off and did a thorough inspection and found the cause of the scraping. The shield behind the rotor was making contact and scraping the back of the rotor. Luckily this was an easy fix. Thanks so much for the suggestions guys.