My motor just started making this knocking/valve tap sound just last nite. When i first got the car the sound was there slightly but only at idle....I got on the expressway last nite for the first time with it goin to the races...and once I got down there it still sounded the same at idle but when i'd take it up to about 3000-4000 rpm it would start makin this sound louder......can anyone help me out as to figuring out what the problem may be??

 

possible spun bearing?

 

could be alot of things man

maybe its outa valve lash?

 

I had the same problem in my CRX B16. I started to notice a thumping sound when the engine is at idle, you could kind of feel it. I noticed this after I changed the water pump after it went out. So it might have something to do with the timing belt, and the amount of play it has in it. I still haven't resolved my problem.