What could be wrong with my 97 Jeep grand cherokee when it makes the terrible noise?

There's this terrible noise that 's coming from my hood of my Jeep Cherokee for some time. What could it be?|||Based on that description............ Hood Gremlins.|||More information need. What kind of noise, what does it sound like, etc.|||Need a lot more info, but I am going to say timing belt.|||Why yes the timing belt. Brilliant. And if the wheels fall off I suppose that is the timing belt as well. No timing belt in a Jeep engine. Could be the timing chain if the engine is very high mileage, but alas, the original poster assumes we all have crystal balls as they failed to give that, or any real pertinent info........