I recently got a 93 EX Accord with 140k miles as a hand-me-down, and a couple months ago I did a valve adjustment on it. The clearance was way too small; instead of .010" (intake) and .012" (exhaust), it was more like .008" and .010". On some of the valves, I couldn't even slide in the next smaller feeler gauge. For example, on a couple valves that were supposed to be .012, I couldn't fit the .010.

A friend and I adjusted the valves to spec, tightened the locknuts with a torque wrench, then put the cover back on. When I started the car, it made very fast clicking sounds. I'm told that this is the sound that valves make when they're adjusted too loose. We went back in there and re-adjusted the valves. This time, We made them almost as tight as possible while still allowing the gauge to slide out (although with some resistance).

Starting the car again, the noise was a little quieter, but not much. We drove around for several miles, and then over to an Acura dealership, and asked the guy on the service floor there. He used to be a Honda mechanic, and he said it sounded like what old engines sound like.

I thought maybe the feeler gauges were off, but I got decent quality ones, made by KD Tools, and the thickness checked out fine with a pair of vernier calipers.

Before we did the adjustment, there was none of the valve-clicking noise. The engine just sounded smooth. Since the adjustement power and gas mileage seem fine, but the sound makes me wonder if something is wrong. Unfortunately I don't know the last time the car had a valve adjustment. Is it possible that it went too long with too-tight valves, and that it damaged them somehow?

Or should I just not worry about it?

 

If you are certain the valve lash is correct then don't worry about it.
There was a tech line Service notice a few years ago titled
"Noisy Valves Are Happy Valves"