Putting/Clunking sound??

[slonova]

Hello.

I started my car after volunteering today an i started to hear a putting/clunking sound you can say was pretty loud at first then kind of died down a little but came back while I driving. Went on a little on an off, luckily I didn't have to go far to get home. Got home looked at a few things to see if anything was loose or had holes or just plain not looking right but nothing that stood out, got on here an started searching away an came across a thread that was talking about transfer cases so now wondering what it is. I have two videos I recorded that have the sound in question in it and i would appreciate your help. thank you
sorry if i missed anything or posted wrong, been kind of stressing about this since I just moved an pretty sure I don't have all my tools with me....
2004 Explorer Xlt 4x4

http://youtu.be/tYtHHXif2qg

http://youtu.be/AS2cCKYyDAs

 

[slonova]

I am pretty sure I have figured out what was wrong now, the belt tensioner. Might attempt to change today an see if that fixes the problem and I will give a update after I finish. Also still open to feed back from you guys

 

[slonova]

I replaced the tensioner an went ahead an did the idler pulley too but still have the noise.... any suggestions gonna try a few more things to eliminate some ideas but I would appreciate some feed back too

 

[slonova]

turns out it was the alternator. hopes this helps someone. Also to help you look for the cause start the car with the belt off to help you to see if you hear the noise to help cancel other things out