Long story short. I had a continuous squeal with my old belt, tried some wd40 and it went away for a bit. Cleaned up the pulley's and changed the belt. Squeal was back from the start but was only once every rotation. I changed the idler and tensioner pulley and same thing, they were bad anyway. I cleaned the old belt with light soap and water and it was quiet for about 5 min. WD40 again and it went away. I hand rotated all the accessories and none of them made the noise. Am I safe to assume that it is a belt issue and even the new one is bad? How can I determine if the tensioner itself is bad without replacing or using a puller tester? Thanks ahead of time for your opinions.

Pour a little water on belt with mtr running,belt will usually stop squeaking. I had the same prob. I think it started after a water pump change. I tried cheap belts,NAPA belts,they all squeaked. Finally bought a Good year Gatoback belt,no squeak since. It was about the same price as NAPA.

Odds are your belt and/or pulleys are glazed. Scuff the glaze off all the pulleys with something like a coarse scotchbrite pad, always worked for me.
I wont use WD40 on belts, it has petrolium distilates and that isnt good for them. Besides you want to clean the surface to stop slipping, not lube it. There is a "belt dressing" made but IMO its a short term solution not a fix.

same issue here. After an alternator locked up, I replaced it, using the old belt that was only a month old. It had an irritating chirp-chirp-chirp that I attributed to a glazed spot on the belt. Replaced the new belt with another new belt and it was perfect for a few hundred miles.

Tensioner is good, so I'm going to try another belt - not the $8.95 Autozone belt thats on it now

When I put the new belt on, I did scuff up all the pulley's and cleaned off all of the WD40. I just looked at the new belt and it does seem to be glazed a bit. Thanks.

Mine chirps when I hit the gas/upshift (its a stick). If I drive it like a granny it wont do it. Tensioner is new, tried 2 new belts...still a nagging problem.

Tried belt dressing spray then somebody told me that is for V-belt, not serp...

Look closely at your power steering bracket if the engine in question is of a Magnum variety. IT MAY BE BENT.. Sounds odd, yes, but over and over again I have seen this. Since I work in the parts business I see silly things and this is one that even Ma Mopar knows about. If you have had an idler lock up, a water pump go, an AC Compressor lock up, or any other situation that stopped the belt DEAD in it's tracks, LOOK at the alignment of the P.S. Pulley. How this happens is beyond me, but it does.

Peace, Rev. Mopar

Goodyear Gatorback

The one on my van is chirping and squealing too, a buddy told me to put Dialectric grease on my finger and wipe it across the rib's of the belt. Worked for a couple days then the squeal is back. I'll be watching for the fix cause i've tried cleaning the belt and pulley's and belt dressing with no good results.

It is actually on a 92 s10 blazer. All of the pulleys are in line but the power steering one wobbles just a tad bit. I thought that could be an issue but turning the steering wheel back and forth does not make it squeal louder. This is annoying for me of course but I would rather have no exhaust then have this thing chirp as loud as it does when I am next to someone, LOL.

I agree with pushbutton on this. I had the same issue with the cheaper belts and after putting on the Goodyear Gatorback, it never squeaked again.

auto zone, dayco poly cog is just as good as a gatorback and they are sold at advance auto

Waterpump or power steering shaft runout can also cause belt chirping/squeak.