I've had that same problem except mine was more of a tiny squeeking noise, took it into the shop and they though it was something with the belt and all and replaced all of that but it wasn't, its more noticeable when colder out and its only when its in idle

 

belt squeak can be fixed with some sort of spray.

 

ok so i went to the crysler dealer near me and had it inspected for what the exact issues are with these noises. turns out my alternator is 90% of cause which i thought was the case after i bought a stethescope...idler is ceased... and new belt ill end up getting anyway. labor from the dealer is quite a bit so im think'n of repairing myself but is it hard to replace an alternator / idler arm-pulley? from what i looked up doesn't seem that hard... anyone have any links that would be good for this? the dealer wants like 300 bucks just for labor alone !. which is like 3.5 hours or so of labor. i k now it doesn't take that long to change this stuff so.

 

i guess we're just lucky my dad has had 2 truck w/ this engine in it and niether one of them ha ticked, and niether does my truck so idk what to say

 

theres one bolt holding your idler pulley on i just changed mine the other day took about 15 minutes the alternator is easy too because its right on top of the motor you mine as well replace the belt too while your at it and a new belt tensioner/pulley

 

yah i figure ill do it on saturday... no point in pay'n crysler 300 dollers for labor for something that takes an hour all together. anyone have any step by steps for changing these parts? i think i can do it without any instructions but just in case.?

 

loosen the belt tension by turning the bolt on the tensioner pully clockwise, take the belt off, remove your coil (it blocks the bolt to get to the tensioner pulley nut) then remove your tensioner. the idler is easy just loosen the one bolt in the center, comes right off. before you take the alternator off just be sure to disconnect the battery and you should be good to go

 

aight so i changed my alt, idler pulley, belt and still i have a rattle type noise. however it is about 50% less noisy. one thing tho.. when we had the belt off i spun the fan and when i went counter clockwise the fan made a kind of grind /rattle noise so i think the rest of problem is with the pully for the water pump behind the fan... im assuming the bearings in there are shot..... anyone know how to take off the fan to get the pulley off behind it?
oh yah i didn't change the tensioner yet cause they didn't have it in stock at the time but the tensioner when i spun it was fine and seemed tight so i figured no need for now.