Some weird noises.

Lately, my 1997 XJ has been making some un-usual noises. I do not know if they are normal or not.

1 - The air system sounds scratchy. It doesn't sound smooth, and at times it can be rather loud.

2 - Engine is clicky. I change my oil as often as I should and keep it in good shape. But also, the engine doesn't sound as smooth as it use to be. It gets worse at higher RPM's.

3 - If I am at a complete stop, and I press on the gas (medium force) There is a short rattle somewhere down by the gearbox or tcase it sounds like. But if I am just driving down a road, or coming to a stop or accelerating from already moving, it doesn't make the noise.

If anybody has any ideas or suggestions, I would appreciate it. Thanks.

Well not too sure about the first one but, the second could be an exhaust leak, It doesnt matter how many times you change your oil, Its not going to stop an exhaust leak from happening, and as for the third, Im not sure if its the same rattle that I have but mine rattles when first accelerating and Im pretty sure its the exhaust rattling but check all your bolts for the t-case and make sure everythings tight.

Exhaust leak? How would I check that? If it counts, when I first start it up in the morning... Liquid/humidity (don't know if it's water, or what) starts to come out of the tail pipe.. but I see that on a ton of cars.

I'll go ahead and check the bolts up under there. Thanks!

This belongs in mod tech how?