Rep Power: 0

Hey guys! I have a 1989 Honda civic with a d15b2 equipped with an integra PGM-FI swap done by a previous owner, who also rebuilt the engine.

When I bought it, it had a bunch of holes and a cherry bomb for an “exhaust”, so I didn’t hear any noise. I have an old video from when I bought it and I didn’t hear it then ether. The knock has been there as long as I can remember, but I guess it has something to do with something I’ve done.

Under engine acceleration / load, the engine makes a pinging / knock sound. It’s worst at cold operating temps and almost goes away as the engine warms up. Refer to the attached video to listen to it. Since it’s started happening, the knock has not gotten better or worse.

What I’ve done to the engine:

• general tune up (plugs, cleaned IACV, set valves, oil, etc.)
• almost full new exhaust, only thing left is the down pipe and flex pipe bit.
• adjusted clutch
• listened to engine with pry-bar to ear (nothing jumped out, couldn’t really hear the knock through it).
• set timing
• varied fuel octane and oil viscosities (no change)
• inspected bottom end (check rods for play, oil pickup for debris / looseness, grime. Didn’t pull rod caps but felt no play and cylinder walls looked great)
• general nosiness (no excessive blow-by, no lose bolts / engine mounts, no loose trans bolts, PCV vent box, stuff like that).
• checked sensors readings, fuel pressure, injector performance, swapped to backup ECU, no change)
• replaced engine ground
• Pulled plug wires one by one, knocked the same regardless of any cylinder being inactive
• removed accessory belts, no change

I’m at a loss. I want to say it’s an exhaust leak somewhere in the pipe from the new manifold to the new cat, as that’s they’re the only exhaust pieces that I haven’t replaced. I suppose it could be something drive train but I have my suspicions, plus I’m not gonna pull the trans just out of curiosity. I may try changing plug wires, but it has NGK blues on it so idk. I have not done a compression test, but when rigged to crank-no-start each cylinder sounds like it builds even compression. Maybe it’s even the timing belt cover hitting something, who knows (belt shows no signs of contact).

This is right after I did a bang up job on painting the basically ruined hood and new bumper.


link for video (Google Drive): https://drive.google.com/file/d/1eGm...w?usp=drivesdk

if you have any good guesses, let me know! It’s one thing to have a beat up old ef, it’s another for it to knock down the road. Looking AND sounding hoosier is not for me.

 
Rep Power: 221

Checked ignition timing?
car looks good dude!