Some 2008-09 Honda models with V6 engines may produce a knocking or ticking sound while the engine idles.
According to the car maker, the noise usually gets worse as the engine warms, and it most likely is due to too much clearance in the rocker shaft bridge, which allows the shaft to rotate during engine operation.
Loosening, then retightening each bridge bolt, should eliminate the noise.
Start the fix by removing the valve cover from the front cylinder head. Now loosen each bridge bolt.
Referring to the top illustration, tighten bolts 1 through 8 to 19 ft.-lbs. and bolts 9 and 10 to 18 ft.-lbs.
As you tighten, it may feel as if each bolt is starting to strip. This is just the bridge crushing against the rocker shaft, and it's normal.