So... I have a 91 RS Camaro. The odometer reads 135,000 miles but I replaced the motor with a rebuild one my boyfriend picked up as a birthday present. All the guy said was that it came out of a camaro similar to mine, was rebuild about 5,000 miles ago, and ran fine when pulled. But once i got this motor in it and started it, it was making this mysterious knock.
I've attached a video link... watch it all the way through, the sond changes as the car warms up. Thanks, any help would be appreciated.


[[P.S, we put in new oil, tranny fluid, coolant, etc. before starting the motor.And excuse my loud friends in the background]]

Mystery Knock

 

Bump..... Not a mechanic by trade but that obviously doesn't sound good. Easy to be a Monday morning quarterback but did you get a written receipt/guarantee? Buyer beware! Hopefully It's not a big deal. Hope things work out for ya.......

 

Sounds like my 97 Saturn when it dropped a valve seat into the cylinder. Are you losing compression and do any of the spark plugs have a bent electrode?

 

I pulled out the spark plugs on that side (It's coming from the Driver's side, if it wasn't obvious...), and they all seemed to be just fine. I guess a double check could be in order.. And I didn't get to check the compression in time, shortly after the video ended the car just kind of sputtered and died. I wasn't exactly too comfortable with starting the car up again after that.

 

whoever put in the engine for you, did they not adjust the rockers correctly, did they forget some push rods or are the cam lobes that worn?

 

The push rods look fine... I checked them, and they are all there, I even pulled them out to make sure they were in sound shape. It didn't even cross my mind that it could be the Cam lobes, though, I've never heard a sound like this.

 

hard to tell, but it sounds like the valvetrain making noise.

 

Really sounds like the rockers need adjusted.