Mysterious engine noise no ones been able to diagnose.

Hi, We have a 1993 Subaru Legacy station wagon, which we love! and don't want to get rid of but long story short is that after doing many repairs on it the cars suddenly making a weird sound that no one has been able to figure out what its due to. Not sure WHAT caused it, what it is, or how to fix it. Can any one help?

More details...

Its kind of an odd squeal / rubbing sound that is inconsistent.
Only happens while driving, NEVER when sitting still, and is on and off, seems to be effected by acceleration but then other times not at all, so its been very difficult for anyone to diagnose. We've tried 3 mechanics.

The first diagnosis we got was that the hub and bearing was bad, which turned out to be true so we repaired the hub & bearing last week but the sound has just continued on. A friend of ours says that he's sure its the sound the car makes when the hub & bearing is bad but again can't be the case. we've re checked all the other bearing and hubs and they're fine.

We just changed the axles & did the alignment last month. The breaks were changed the month before.

Due to a leaky radiator and my younger brother forgetting to check the water; it overheated and turned off on us on the freeway about 2 weeks ago.
Started making the really weird loud engine noise soon after. But not sure if its related to the overheating? or if it was some how caused by/during the repairs? or what :/

Other then the noise, the car is running relatively smoothly. We're not sure if its dangerous or not but its our only car and we're afraid its going to break down on us if we can't figure this out.

We have to drive a long distance to work this coming Wednesday and so are desperately trying to solve it.

Any thoughts would be appreciated! Thank you!

auto trans right? mines doing the same . Thinking flexplate? Ive seen quite a few over the years crack right the the crank bolt pattern , and they only slip under heavy accelleration, untill they finally free spin. I'm just pussyfooting mine until I can replace the trans (worn 1-2 clutch)

If you could post a YouTube video of the sound, this would be most helpful.

drive it to me..... ill diagnose it..... I ALWAYS figure noises out that no one else can find..... theres so much that can cause noises when driving.... even cupped tires can be missed so many times yet cause noises.....

does it kind of sounds somewhere in between glass being cut and rubbing your finger on a crystal glass rim?

only happens at the start of mid-low acceleration, and disappears with heavy acceleration?

mine does it too i thought it might be related to my breaks but was going to wait until i replaced them to rule it out.

Take a video and post it on youtube.