I swear if I didnt have bad luck I wouldnt have any luck at all. Not only do I have to replace my cracked wheel, I now have the worst engine knock I have ever heard. Runs fine all winter until yesterday afternoon. Driving about 20 mph down some backroads behind my buddies tractor, I hear it knocking extremely bad. Truck never overheated, nor lost any coolant. I think its the water pump but as of now I have no clue. Im going to see if I can attach a video I took of it.

http://s1164.photobucket.com/albums/q579/nrd10/

 

I would remove the serpentine belt and listen again, at least that would eliminate a few possible causes. If it is still knocking without the belt then it has to be something internal and would eliminate the water pump, power steering, AC, fan clutch, alt, and idler pully. That would leave the guides or tensioner or possibly the oil pump or worse it could be a bad rod or main bearing.

 

So I can take off the serp belt and then start the motor again and have it idle for like 30 secs and not damage anything?

 

You'll be fine for long enough to see if the knocking is still there. It won't even get hot in 30 sec without the water pump running. Just make sure you got a good charge on the battery before you try it.

 

Thanks for all the help guys. It was the smooth pulley on the driver side valve cover to the right of the alternator. Turns out the ball bearings inside came out somehow which was causing it to wobble and the belt to walk on the pulley. 20 bucks for a new one and its good to go!