Solved - Belt Squeal -Not @ Start Up, Happens @ Speed

Got an interesting one folks! (Can't even find this one from other forums OR the SEARCH:

I get belt squeal over 50mph (timed it at 70mph) and the squeal happens every 28-30 seconds.
Belts feel good (and replaced a few months back w/Continentals and done close to 7k on them already (Checked at a shop and they said the belts feel right).
I do not get belt squeal @ start up!
Only when I'm over 50mph.

Brainstorming: If the belts were either too tight or loose, would I feel something like a transmission hesitation? Ever so often at freeway speeds, the transmission seems to "hiccup" where it backs off for a second. Could those be related or totally separate? (Its an automatic transmission) Another 'symptom' is the idle is a little higher than normal, even after warmed up. Could be unrelated.

Any Ideas?

 

How many miles? Has the timing belt and water pump been changed?

 

Thanks for the reply. 178,011 currently.
No history before me, sadly.
Timing belt looks good (the belt at least at 177k, when I checked) Water Pump, not sure.
Maybe a pulley gone bad?

 

I appreciate the suggestion.
As I mentioned, I replaced the belts with Continentals between 5-7k miles (Oct-2018). I replaced the A/C Compressor, as well.
However, I did not replace the idler pulley -- I'll check that.
Would a bad idler pulley cause a squeal on automatic downshift at speeds above 40-50mph? Or is there something else contributing?

 

Thanks -- I'll check the idler pulley and tension on the A/C belt.

 

Solved - Tightened up the belts more -- good to go.