I just bought a 1998 Civic EX d16y8 5 speed for $1200 off craigslist.
When I took it for a test drive it wouldn't go over 3000 rpm and had no tick or knock(It was low on oil and added some and now it goes past 3000rpm). I had it towed home and replaced plugs, wires, cap, rotor, catalytic convertor and replaced the header and exhaust with all stock. I also added a can of seafoam to the vacuum and tank. I added marvels mystery oil to the oil before I changed it. NOW I have a tick or knock at 2000rpm when cold and after it warms up I can hear it at idle and all the way to 3500rpm any higher and it goes away. When I bought the car he told me it would need a new cat...the surprise was there was a hollowed out cat. The sounds are coming from between the valves and piston heads. it has typical valve noise which you can hear in the video and it doesn't sound like bad rod knock. It also smells like its running rich. I have checked the timing with a light and torque Pro and it is dead on 12° BTDC.
Thanks in advance for your replies.

 

Does sound like a bearing knock, how much oil did you end up putting into the motor? Usually anything that does not go over 3000RPM should be a Sensor Problem Most likely a MAP sensor or TPS sensor. Start out with a CEL check, even if it does not throw a CEL. then check Connections on Sensors and Also Check the Amps. When was the last time it had a Valve Lash??? Other than that, the Video surely sounds like a Bearing knock

 

I added a quart of oil when I first got it. There are no CELs. I searched the internet to test for spark knock and I pulled the #1 cylinder wire and ruined the coil which I replaced. Also when I pull the #1 injector plug the sound goes away. I did a valve adjustment when I bought the car.

 

#1 cylinder is where your problem is. good troubleshoot. now take the car and drive it through dudes house!! j/k . get it done fast before you throw a rod or something.

 

I bought it for the body which is straight and planned on doing a rebuild(which I have never done) or replace the motor with a Japanese motor. I would like to just rebuild it for the experience. What is the rebuild difficulty?

 

depends on your mechanical ability and resources. and what kind of tools you have. count on it being down for a couple weeks if you don't already have every part you need at the beginning.

 

I would say im a little above intermediate..I know the easy route is to just replace it..but im up for the challenge..nothing like busting some knuckles and saying a few swear words.

 

lol sure. pulling the motor is no problem. dissembling it is no problem. putting everything back together takes some patience and know-how and some cash. maybe some machine work if mating surfaces are not true. find a free service manual for the car online.

 

Could this sound be a sticking valve after warm?