Strange noise from engine starting at around 1800 rpm. Kind of sounds like a ping or misfire of some sort. 1993 Accord with manual tranny. EGR is good and the ports have been cleaned twice. New NGK plugs, wires, cap and rotor. Runs great. No dead spots or surging. Just noise. 150k on the clock. Noise increases when under a load. What could it be? I know it is not a heat shield rattle. Definately internal. Valve lash has been adjusted. Thanks.

 

A "Ping" noise under load is generally pre-detonation, also called spark knock... you might try running premium fuel to see if that stops it... if it does, you definately have spark knock and may have too "hot" of a spark plug, or excessive carbon buildup on your pistons... has the head ever been milled? that can raise compression and cause spark knock...

 

Timing ever been checked?
Can you hear the noise when the engine IS NOT under load, as in revving in neutral?

 

The noise is there when not under a load. The engine has never been appart. The timing has been set, but I have an advance **** on my light and not sure if it should be dialed to 0 when checking the time. Followed the Chilton manual directions for setting time.