The normal lower radiator hose is about 15" long, going to the radiator. I thought you might have an oil cooler, which has two hoses, one from the radiator, and one very short(6" maybe) one to the WP.
You can now see how much trouble it is to get down to the timing cover. I doubt anyone has changed the timing chain before, they likely won't "fail" before the other engine parts. But they get loose after a while, and at 100k they are plenty loose. When you get the cover off, you'll be able to twist the timing chain and decide if you think it's still tight enough.