I searched f150online and other websites (about 3 hours) and could not find anyone experiencing the same noise (rattle) that I encountered and cured on my 2000 F150 XL 4.2L 82k miles.

This post is written as a courtesy post for those who may be looking for a solution to the common belt/pulley noises that we all encounter on our Fords.

Noise started as a slight tapping sound (like a plastic bead inside a pvc pipe being shook real fast). I isolated it to the AC compressor or ps pump as the noise was coming from the drivers side. It got worse over time to the point that I was afraid to drive it any long distances.

I bought a rebuilt pump from autozone, transferred the pulley using the correct puller set. Noise was still there and even worse with new ps pump. I looked and checked everything under the hood to find where/what the noise is with no results. I swapped belts too. I notice that our pulleys are made of plastic, so I decided to buy a metal one (Dorman part number 300-010). Installed the metal pulley and presto the noise was gone. I was beginning to think I had an internal problem (cam synchronizer, phaser, timing chain, etc.) but it just turned out to be the plastic pulley. I believe that it has a hair line crack that expands when it's spinning, thus creating the tapping/rattle noise.

I hope this helps the next guy who hears this funky noise.

best regards....cg22.

 

Nice catch.

 

I cleaned the plastic pulley thoroughly and looked for chips, cracks, etc., there are none. The only conclusion I can make at this is that the pulley has a metal center that is pressed into the plastic pulley.....I believe that when spinning, there is a slight separation of the metal center and plastic pulley resulting in a ticking/rattling noise.

Hope this helps those who may experience this annoying noise.

 

You replaced the power steering pulley? I've been going nuts looking for the source of this noise. Very helpful post for me

 

I had to replace my grooved plastic idler pulley because of this similar noise. This was when I was also having alternator issues. I found that noise using a stethoscope.

Why would they use plastic on moving engine parts is beyond me...