Making a funny noise from the bottom of engine

Your instinct sounds right.

Has the performance of the car changed as well?

Change the oil and use a clean drain pan. When you empty the pan, look for metal in the last bit of oil and see if it is silver or brass in color.

Silver is the first layer of a connecting rod or crankshaft bearing. Brass color is the second layer of those bearings and the size of these particles also indicate how bad the condition of the engine is.

Let me know what you find.

You can also use a long screwdriver like a stethoscope. Put the tip near the area where you hear noise and the handle to your ear. You have the, "Ear" for these kind of problems and you will get a better idea of what is going on by doing this.

Also feel the engine in areas where you hear the noise, (where it is safe to do so) and that will give you some clues as well.

I will keep an eye on this post for your reply. Let me know how it goes, what you find and any questions you have.

I will get back to you ASAP.