I have a 99 Buick Park Avenue. When my car is warmed up (no noise the first 15min of driving or idling) it starts to make a squealing noise, something like a belt noise, but it isn't the belt. The noise is coming from the flywheel area between the oil pan and the flywheel. I've used WD-40, spraying the area between the flywheel and oil pan, then the noise will cease briefly then start back up after (it seems) the WD-40 wore out due to friction. I have ideas but putting them together to figure out what to fix. Different mechanics tell a different diagnosis: one is expensive and the other is doable. Could it be the bearings in the motor? Thank you to anyone that could help.
There is no way, to my way of thinking, this could be the bearings in the engine. There is absolutely no way you could get any type of penetrating oil into the bearing area of the engine using any type of spray means. These areas are sealed against outside contamination by means of a seal and oil pressure (meaning, if the seal starts to fail, you'd see oil coming out so the dirt or other debris doesn't come in).
I'm wondering if the problem is with the torque converter and not the engine? Again, not a real answer, and not something which would be solved (even briefly) with a squirt of WD-40.
What I'm thinking it could possibly be is that the starter is not disengaging properly after starting. You said the noise starts a period of time after the engine is started. If the starter has gotten to a point where it is hot enough, it might start making noise at that point and continue to get louder as time goes on. This is a real stretch, but seams feasible.
I'm afraid without further explanation, there's not much more in the way of an answer we can provide for you.