Pulley Issue 2001 XJ
 

Another problem. Jeez, I never had this much trouble with my '92!

Anyway, just finished doing a cooling system overhaul and I see that the pulley where the compressor is, the large upper pulley on passenger side, is moving intermittently. There is a constant whining sound (not sure if it's related), the pulley turns for a few seconds then it stops. It would take several short jumps to make 360 degrees. Keeps happening over & over as long as the Jeep is running. I checked my '94 and this part does not move at all.

I don't know if this functions differently on an '01, so could someone clue me in? I don't think this part should turn, but if it should, it only turns for a second & then it stops. The belt doesn't seem to be affected. What would cause it to do this? Is is simply a matter of tightening some bolts or is something shot?

I'm pretty sure that's the compressor engaging and disengaging. Try turning off the A/C to see if it stops. The whining sound could be the power steering pump. Mine sounded like a crappy supercharger when it was going bad.

The AC has never been on since I bought it. That said, I'm not even sure how to turn it on in the '01. Controls are different from my other vehicles and there isn't a switch that says "AC".

I'm more concerned with the pulley tho. What's wrong with it?

Any time the middle dial is on a blue icon with a snowflake next to it, the compressor should be engaging periodically. You can turn it off by moving that dial to the left most position to "O."

It maybe a bad bearing inside that pulley. Try taking the belt off and spinning that pulley by hand. It should be nice and smooth.

^ What he said. Remove the belt and check the pulley. Dont just spin it. Look between the pulley and clutch for rust as there could be buildup in there catching the pulley. You will have to remove the clutch and wirewheel it if there is. Dont lose any shims (they look like washers). While you are in there, check the other pulleys as well. Just because.

This is what im talking about.

if its

I believe it does, I didn't mention that before.

I appreciate the insights guys. Getting a better understanding of what's going on. I've been working on the cooling system ... checking the heat - running the Jeep with heat on high and so on. I'm done reassembling the new hoses, w. pump, t'stat, all put back together, but still doing the final flushing to cycle out the liquid that's in the block before I put coolant back in it.

This morning I noticed that the pulley turned fully like the others, but only when I turn the heat on - and by heat I meant that I use the position on the dial where it shows defrost as well floor heat. When I turn it off, it stops and goes back to what I described in my first post. I've never turned on the AC since I bought the XJ, but I do agree that the defrost function is what seems to be triggering the pulley to turn because it seems obvious that it's supposed to keep turning along with all the others. I'm not keen on taking the belt off again - it's a devil getting it back on & tightening it to the right tension. I'm not even sure if it's at "correct" tension right now but it seems pretty tight.

You guys are freaking awesome. And I'm proud of myself! How many other women do y'all know who overhaul their own cooling system ... and I don't mean just flush. Learning a lot.

Get yourself a Gates Krikit II belt tension tool, part #91132. New belts should be set to 180-200ft-lbs, and a used belt is closer to 160.

https://www.cherokeeforum.com/how-to...lipping-399129

Check out the rest of the How-tos section near the top of the page. I keep forgetting its there, but there you go.

belt is ok huh...

belt is ok..run it a while first...

Not sure I understand this last comment ...

why

Defrost setting turns on AC compressor, regardless of temperature setting.
Be sure to not use tap water for the final fill of cooling system. Use distilled water and full strength coolant or premixed coolant.