My bro just picked up a 99 Accord coupe 5-speed on Saturday, F23 engine. He put in some NGK G-power plugs, the correct one for his car according to the NGK website, and reported some strange knocking/whining sounds after starting it. He did check and adjust the plug gap accordingly before putting the plugs in.

So then he put some NGK V-powers that he used in his del Sol D16Z6 and it seemed to run better than the correct G-powers for the Accord.

Any idea why the correct G-powers for his engine would cause that? Are those plugs known to cause any issues? I have always run V-powers for years in my Integra and never had any problems.

 

NGK come pre-gapped so if he re-gapped them that could be an issue ... but i dont think it would cause any knocking or whining noises ... i have only used v-powers and iridiums so i dont know about the g's