Knocking / rattling sound after replacing rocker arm
 

Hey there. I have a 99 Civic LX with about 190k miles. Several months ago, I had a cam seal leak, which I replaced by removing the camshaft. When I reinstalled it, I re-adjusted the valve clearance, but noticed one of the adjusting screws was seized in the rocker arm. A week later, I replaced the entire rocker arm, screw and nut without an issue, redid the clearance (0.009mm on intake, 0.011mm on exhaust), turned the crank several times to make sure everything was rotating smoothly, and that the valve lash clearance remained within spec.

Ever since replacing the rocker arm, I have increased engine noise. It's difficult to explain over text, but basically, you know how a cold engine sorta knocks until it warms up? Well my engine continues making that sound even when warm, though it does decrease a little once is reaches operating temperatures. The sound increases in speed with increased RPMs.

I'm not sure what I can do... maybe I messed something up, or somehow skipped a tooth on the timing belt? It seems like the engine has the same amount of acceleration without and stuttering or anything like that. Anyone think I should be concerned?

I'm sure that you already know this, but adjust the valves only when the engine is completely cold. The specificatlon takes into account the expansion of metal that tends to make the clearance smaller when the engine warms up. If you adjust them while it is hot, they will be too loose.

I did it while the engine was cool, though I do live in scorching hot Texas! I rechecked my timing and it was pretty far off. I had to advance it quite a bit and it seems quieter, but I haven't done a cold start yet... can timing affect the knocking sound?