I have a 97 honda civic dx. I just installed a used engine with 116000 miles on it with the d16y8 intake. I have a knocking noise when the engine gets warm. As I accelerate it goes away. I've been a auto tech for 20 years but this one I need help with. It sounds just like a rod knock but goes away with increased engine rpm. I'm wandering if it's a main knocking. It will knock at idle and under deceleration and at idle when the ac engages. I've checked the flywheel bolts and crank pulley. All is tight. The rear main also starts leaking when warmed up. Anybody have any ideas? The motor runs really strong. I've really went out and abused it just to see if it got worse and it didn't. But it's annoying me and I don't want what happened to the last engine to happen with this one. The last one threw a rod thru the block.

 

try turning the motor by hand to see if you can find the noise. if it is a bearing you wouldnt really want to run it until you have it fixed. i havent tried it yet but i have the same motor. pull the oil pan off and turn it to see if you can hear it that way. it wouldnt hurt to check the bearings. it might also be piston slap and increased oil pressure from accelerating might be stiffening it up.