I got a 93 civic ex that i bought without a motor. I put a used d16z6 in it and it ran and sounded great for a week. Now it has a low end knock. Its a automatic so you can hear it knock before the trans shifts gears. If you rev it up just a little you can hear it knock but it dont do it at higher rpm's. Does this still sound like a rod knock?

 

Pull the oil pan and stop speculating. Maybe even get on Youtube and find a click with rod knock.

 

Try pulling spark plug wires one at a time to narrow it to a cylinder. Don't rule out a loose or missing engine or accessory mounting bolt or other sources that can create a knock.

 

Removing plug wires would help diagnose a miss, not a knock. It also risks frying the distributor. Not only would that test be diagnostically worthless, it might set the OP back a nice chunk of change for a replacement.

How about we don't do that.

OP, drain your oil and look for metal fragments. Buy or make your own motor steth, and narrow down the exact location of the noise.

 

Momentarily pulling a single plug wire is not going to immediately roast your coil. The energy will dissipate to the next plug that fires. It is one of the oldest troubleshooting techniques around for diagnosing an engine knock (yes you can also identify misfires in this manner).

 

Too many people posting about blown coils after doing just that. Sometimes you're lucky.

 

Maybe after a compression test. If you're paranoid put an old plug in there and ground it.