I have a 98 civic with d16y8 engine. The ticking noise is definitely coming from under the valve cover. I have put a new timing belt on it and set #1 cylinder to tdc. After that I went ahead and did the valve lash clearance. I made sure I used the correct specs for valve clearance and made sure the valves I was doing were on the compression stroke. The ticking noise is really loud and if I rev the engine up even slightly it sounds really really terrible.