hey so i have a 1997 Honda Civic Hx that i bought knowing it had a knocking engine i figured it would be a good project car..... the owner said she had a mechanic look at the car and it was definitely rodknock so i started by replacing the main and rod bearings which wasn't in bad shape at all.. they where worn but not spun. while i was at it i noticed that the pistons where in bad shape so i replaced them as well(im pretty sure she overheated the car because the piston had melted over the rings) i also honed the cylinder walls because the pistons beat them up which i figured the knock was coming from but when i got it all back together it still has a knock/ping and it also surges when i rev to 1500 to 3000 rpm. today i adjusted the valves and cleaned the IACV and it didn't help at all... im not sure what else to do any suggestions would be much appreciated i have added a sound clip from the car if that helps any

 

I would suggest replacing the crankshaft. I have a 1997 Honda EX, and revved way too high with almost no oil, one bearing spun and melted