I've been thinking of changing my valve cover gaskets in my engine, as they're leaking a little oil and I can smell it burning when I drive. I think I heard that the timing chain is somewhere near this region, so I was wondering if it'd be a wise idea to check out the timing chain while I have the valve covers off? How can I tell if it's been recently replaced or if it needs to be replaced? I've heard that the damage of not changing it when needbe can be pretty disastrous. Also, could anyone post a step-by-step procedure of some sort to go about changing the valve cover gaskets? It looks like it'll be a pretty straightforward job, but if anybody has something to say to help me out, it'd be greatly appreciated. Thanks.