newbie here, need help trying to diagnose a LOUD screech noise my jeep has started doing recently. its a 2000 4.0 Auto with 126k. at idle when I rev/bump the throttle I will hear a loud screech, almost like metal on metal. it also does it while accelerating somewhat hard from a stop. i plan on doing the work myself but need help on where i should start. i thought maybe the belt and then check the pulleys??? any help i would greatly appreciate.

sorry if this is in the wrong area to be posting this.

Remove the serpentine belt and make sure all the pulleys and idler spin freely.

Check your belt. Might have become loose, or you may even have a pulley seized/ing up. I had a very similar sound with mine and it turned out to be the idler pulley was shot. Hardly wanted to turn and would screech when I gave it gas, even worse with more.

EDIT: Ahh, Turbo beat me....

thanks guys, that's what I thought it could be but wasn't sure. ill be tackling this first thing tomorrow morning. im hoping its nothing too serious but I doubt it, the jeep runs great except for the loud screech, doesn't always do it either. ill keep you guys posted, tried posting a video but couldn't get it to work. thanks again.

1st thing make sure your belt is tight.

Like was said, check ALL the pulleys. Especially the harmonic balancer. It is a two piece design that caj separate. The belt has to be stupidly tight.

They sure can, ask me how I know. I just spent the first half of my day replacing mine yesterday. I had a strange squeak/screech sound I was trying to locate and on my way to work yesterday it separated on the freeway.

Miles