Ok I have a problem with my automatic 98 4.6 2X4 also. When I first crank it up in the mornings it makes a loud screeching noise kinda like somebodys in the words trying to call a bird or something, very irritating sounds like maybe expander pulley or idler or maybe water pump? not sure just figured somebody else might have the problem. It also does it while I am driving it but only when I get on the throttle or off of it. Either way its definitly not just belt noise.

 

sorry forgot it also makes another noise only does it a couple of times a day usually after Ive driven it somewhere its kind of like if you had a bunch of marbles in your hand and were beatin them together, not spark knock something outside the engine I believe not sure any help is appreciated. Thanx

 

I have a 98 too. and i had the same noise. I replaced the idler tensioner and all was good.

I purchased the the idler pulley and mounting arm. Autozone wanted 60 for the idler only, but 45 for the arm and idler pulley.

good luck.

 

Remove the belt and see if one of the idler pulleys isn't bad. Loose bearings will be apparent when you move them fore/aft. Cheap replacement at the parts house.

 

Alright I figured thats what it was I was really hopin it wasnt the water pump since its 60 bucks and smack dab in the middle. I took the belt off yesterday and spun the pulleys the idler only turned 1/2 of a round and all the others turned 1 or 1 1/2 so thats probably it. Ill get me another one and put it on and see if it solves the problem. Thanks for the help I preciate it.

 

Well I went and bought a new idler pulley today and installed it real quick let the truck set for an hour or two crunk it up and wuppity doo same thing still screeching and chattering, guess the expander is the next in line for replacement. I guess Ill do that tomorrow or somethin. Ill keep the thread updated though for anyone who may have the same problem in the future. Wish me luck!

 

Alright today I bought a new expander pulley and installed it (took 2 hours not bad for 3 bolts) anyways did the same thing let it cool crunk it up and it screeched really bad I revved it and at 4 grand it does it consistently, not good to rev it up like that but I took out some of my anger and found that out so its justified i guess. I think im actually going to take it to a mechanic now I need a freon recharge anyways.