98 Exp 4.0 SOHC Oil Leak from Timing Belt Area

I just recently discovered that my engine had started to run really heavy with lots of vibration. The engine also started to smoke, however, the temperature of the engine was ok and it wasn't overheating. When I opened my hood the smoke was actually coming from oil being burned or evaporated off the hot engine. Also the timing belt is making a wierd bicycle chain type of noice like its clicking against something. However, the timing belt chain is in good condition. There is oil leaking from somewhere around the timing belt chain and emptying out. By the time I got my truck to a mechanic the oil was almost bone dry in which we added some oil just so that it would not sieze. I'm just wondering if anyone has had a problem like this. Is there a gasket of some sort that is located in this area that is allowing the oil to leak from timing belt area? Why is the timing belt making wierd noises? Might the engine block be cracked? -- It has 97,000 miles. The mechanic looked at it for 5 mins and said it might even be too damaged to even fix and might be worth a look at replacing the whole engine, but he'll take a closer look. Any info regarding this is appreciated. Thanks, Zach

Each camshaft has a seal behind the gear. The crankshaft also has a seal. Change your bad seals before losing wour engine. The labor is what will cost you money.