2009 Rogue squeals when AC is on

[Rockhoundrob]

The serpentine belt split along the grooves and came off.
When I removed the belt, I notice the tensioner pulley was offset. The bearing was going bad.
So I replaced the tensioner pulley and serpentine belt.

Now there is a squeal for 1/2 second, when I move forward from a standing stop.
It also squeals all the time when the AC is on (compressor is engaged).

So I believe it is 1 of 3 things...
1) Belt is contaminated (there was a bit of gunk on the engine and some could have rubbed on the belt).
2) Tensioner is too tight or too loose (defective).
3) The AC compressor has a problem.

I am leaning towards 1 and 2 since this noise did not start until I replaced the belt and tensioner.

Any ideas how to narrow it down?

[VStar650CL]

The fact that it does it at all with the A/C off pretty much leaves out the compressor. The extra load from the compressor is just exacerbating whatever is actually wrong. I think I've seen one tensioner bad out of the box in my entire career, so that's pretty unlikely too. My first thought would be that maybe they sold you the wrong belt. Since the old one split, it's also possible the belt is riding on top of hardened rubber debris embedded in the grooves of one or more pulleys. The industry calls that "hydroplaning" even though it has nothing to do with water (go figure). The cure for that is a stiff wire brush.

[Rockhoundrob]

Well now that you put it that way, I think I'll take the belt off and scrub everything good.
Then get a different belt from a different store and see how it goes.

Thanks again.. and I'll update this one way or another.
I can"t be the ONLY one that ever had this problem...

[Rockhoundrob]

Well....
When I got ready to take the belt off, I noticed I could move the belt a bit with my fingers.
Took it off and checked the specs and it was 71.70". I looked on line and 2 stores says this is right and listed several belts with this length.
When googled 2009 Rogue specs, it calls for 71.1".
So I went to another store and got a Dayco that was 71.06" and NO squeal!

I did brush the wheels and there was some black dust. Every little bit helps!

Thanks again VStar!! Making me focus on the belt.

[VStar650CL]

[itsa300zx]

Always match the new belt with old before installing. I ran into the same issue on my last belt change. New belt from auto parts store was about 0.5” longer. Put the old one back and ordered the right length from Rockauto.

Thanks for the updates, it’s great when members post there solutions. So much more helpful tan leaving the post hanging.

[VStar650CL]

Parts stores rely on the aftermarket manufacturers for cross-reference info, and as y'all found out, that info isn't always right. The most infamous head-scratcher in that regard is probably the transmission filters for the RE0F09 CVT's in the Muranos and Maximas. There was a change in pan depth between the early models (deep, finned-aluminum pan) and later models (shallow, stamped-metal pan), but for a long time, a great many parts store catalogs showed the same "deep" filter for both. Unfortunately, if the person installing it didn't notice the depth disparity, that put the pickup jammed against the stamped pan and completely starved the pump of fluid. Result: New filter = Car doesn't move.

Trust your eyeballs. If it looks different, it probably is different.