[kaisen]

Four pieces to this puzzle.

First, it's a Honda motor. Why they don't have hydraulic self-adjusting valve clearances and a timing chain only Honda knows. BUT they are known to be out of spec at relatively low mileage. According to techs I know, they typically see the intake valves being loose and the exhaust valves tight. Only 'loose' valves will tick. Loose valves don't typically hurt the motor, but they could hurt driveability or cause a rough idle, and in rare instances can hammer valve seats. Tight exhaust valves, however, can cause BIG issues as the valve takes the heat but can't dissipate it by heat-sinking it to the head.... it doesn't 'seat' long enough (or at all) to make the heat transfer. I've seen many Hondas and Toyotas burn up motors because of this. At least Hondas are mechanically adjustable. Toyotas use non-adjustable shims that you need to buy the right shim puck.

Second, it is possible (not likely) that the noise isn't a loose valve, but a warped upper cylinder bore from poor heat transfer from a tight exhaust valve. It is an issue with 3.5L Hondas, but very rare.

Third, you can do the valve check and adjustment yourself. It takes about 4 hours. If you just do the front bank (where you said your noise is occuring) it's well under two. They should be:
Intake: 0.20 - 0.24 mm (0.008 - 0.009 in.)
Exhaust: 0.28 - 0.32 mm (0.011 - 0.013 in.)

Fourth, expect to pay a little over $500 to have it done at a dealer.

SO, seeing as you just bought this, you need to DEMAND that they look into it. I'm not Mr Doom and Gloom, it's just that the possibility of a serious or expensive issue does exist. And you don't want to assume that risk. Complain about the symptom (the noise) and let them tell you their thoughts. Maybe they'll happily pay for an adjustment. You won't know until you try.

E