Squealing 96' Mustang

I have a 1996 Mustang with 160,000 miles. 3.8 v-6, automatic transmission. Has a high pitch squealing especially when idling and low mph. eases off some when pick up speed. No pattern that I can find. Have replaced the serpentene belt twice since this has been squealing (approx 18 mo, approx. 35,000 mi), the bearings in the alternater, idlers, the tensioner (twice) and now, a water pump. Still squealling. Have had 2 life-long mechanics look at it and they are both stumped. One thinks it might be coming from the inside front of the engine (Yikes!) don't want to tear into that when not for sure! Just not sure what to check next... Help! They (mechanics) have found that there is an external oil pump and have considered checking this next...

FYI: At just over 50,000 miles the gasket blew between engine and radiater, lost all coolant, blew the engine. Ford replaced engine, oil pan, etc with an adjusted price for me. Later a recall came for that faulty gasket and they refunded my expense.

I keep my car on the road and need it running correctly & DEPENDABLY!
I sure could use some help solving this mystery.

sounds exactly like the same problem i'm having with my zx2. when idling it squeals like there's not tomm, especially when its cold. and after driving for a while, it stops. i've had mechanics tell me they're stumped and i ran across a posting that said it was the torque converter sticking. they were somewhat skeptical by the diagnosis but it very well could be the problem. the sound seems like it's coming from very low under the hood. if you've found out any more since your post, please let me know. i'm still stuck.