Guys, pls give your inputs/opinions on this one: My Honda CRV 1998 on 53,000 miles with 2.0 liter ("B" engine, I believe) suddenly made loud ticking noises 2 months ago. The engine vibrated a lot and I'm surprised it did not illuminate the check engine light. My favorite auto repair was only a few blocks away, brought the car to him and he pulled the cylinder head. He found one exhaust valve on #2 cylinder to be bent. The timing belt had been changed a year earlier but valve and spark timing were dead on. (We made sure we checked that.) The timing belt was an original Honda part, didn't have any missing teeth and it surely couldn't have jumped a sprocket or two without being obvious on inspection now. The tops of the pistons of course had some carbon on them, so a rotary wire brush was used to get 'em cleaned. I looked very carefully, but there were no marks on the piston tops . After scratching our heads on what could have caused the valve to bend, the valve and its valve guide were changed. After everything was back together, I personally observed that the correct valve lash was adjusted (.006" for intakes and .009" for the exhausts)and I myself used the timing light to make sure spark timing was right as per the manual. Firing her up, everything was sweet. Today, less than 500 miles later after the above scenario, I noticed a slight vibration of the engine at idle, but not at speed. Opening the hood, I heard a perceptible ticking sound that warned me loose valve clearance. There's no power loss or engine miss. I brought her back to the same mechanic and we found an intake valve on #4 cylinder that wasn't closing as we turned the engine crankshaft nut. Looks like another bent valve! I, he, nor the machine shop that did the head has ever seen anything like this. The car's an automatic, never overheated, has never been used for towing, and is babied - hardly ever sees anything higher than 3500 RPM. I use the correct oil and gas, and observe correct and timely maintenance schedules. The only thing I can think of right now is bad valve metallurgy, however far fetched it may be. My plan is to replace all 15 remaining valves and possibly their valve guides as well. Comments?