Bad timing belt or water pump?

Hey guys so I have a weird rumbling noise comming from somewhere near the fan, radiator, or inside where the timing belt is. My 2001 3.4L TRD started driving slightly different today. I kinda scensed a loss of power, kinda felt like it took more work for the engine to get the tires moving. Anyway I do have really old and cracked drive belts that go around the PS pump, one goes around the Alternator, and the other goes around the AC compressor. I can't tell if the rumbling noise is comming from the radiator, the fan, the belts, or the timing belt and water pump area.

My main question is does anyone know what are some symptoms of a bad timing belt or water pump? Like I said I noticed a slight loss of power today, also when I was driving home I noticed it started to idle a little more rough. Not seriously vibrating the truck, but more than usual. Also can still hear that rumbling sound I can hear it best when my ear is close to the radiator I between the fan and the engine. I do know that it's not comming from the engine.

 

A bad timing belt makes no noise it just breaks. When you replace the bad drive belts. do them one at a time and listen when the belt is off try the next one and so on. If the noise is still there it's some thing under the cover pump or idlers.

 

The radiator fan is mounted on an idler pulley that's bolted to the engine. This is not inside the timing belt cover, but it's a big metal piece in the front of the engine. If the water pump or one of the idlers is starting to jam up it can make the idle jump once in a while.

Get a really long screwdriver or piece of wood and hold one end on the idler and the other end on your ear with the motor running. You will look ridiculous, but it will help you find the noise. Also, you can get a mechanic's stethoscope to locate the source of noise. It's good for checking to see if injectors are working too.