joycie,
I have said it here many times...."It's difficult to diagnose descriptions of sounds because people have different perceptions of sounds coming from their vehicles". What sounds like a squeak to one person may be described as a squeal to another. A rumble to one person might sound like a groan to another...a knock may be described as a click, etc. But at least they are all similar enough to make a guess.
Comparing the sound of your AC fan to "a Toyota without an exhaust" makes no sense. While an AC fan can rumble or rattle if the bearings are bad, it certainly would never be mistaken for any vehicle engine without an exhaust. It's just an extreme exaggeration and so far fetched that most people doubt your description of the sound....Also that is probably why you did not get many replies....???
I did not have a hair across my a$$, or I simply would have just said: "Maybe you just need to put an exhaust on your AC fan." :grin:"
I don't think my suggestions were out of line, and even expanded upon Eddie's reply. I was only trying to point out that your description of the sound is way beyond the relm of reality and does not help in the diagnosis. Had you given a more accurate, and more believable description of the fan sounds, you may have gotten more help from other here who may have had similar problems and knew exactly what the problem was.
All that Eddie and I could do was take a wild guess.
...Rich