LS3 sound like it’s popping popcorn

[Timberline]

I have a new GM crate motor LS3 525 and the first time I started it the engine purred like a kitten. Two weeks later I finally get back to take the car for a test drive and it sounds like it is popping popcorn out the pass side tail pipe.

Clarification I didn’t get the car out of ten drive way. Rev it easy to 2000rpm let it go back to idle it pops several time. Slowly take the revs to 3000rpm slowly bring it back to idle it pops even when the revs are climbing.

Any ideas where to start looking?

[randy]

Any check engine light? Do you have access to a scanner? Can you view any misfires? Can you post a video?

[carkrazy1987]

scan tool, check for a misfire. check make sure all your spark plug wires are on tight, none backed off. post a video if you can

[Timberline]

Thanks
the check engine light did come on mid way through the run will check plug wires again.
I did have a 13 second video but it wouldn’t load.
Don’t have access to a scan tool.

[dhutton]

If you are going to mess with cars like this you need to spend $50 on a scanner that can reset codes.

Don

[randy]

Guessing a plug wire came off. Unburnt fuel entering the chamber causing popping. Need a scan tool. Go to any parts store or Walmart and pick one up. If you were local to Dallas I would help you

[Timberline]

Thanks will be picking up a scanner. I did check the plug wires last night and the boots were as they should be on the coil pack and plugs. Pulling the plugs tonight to check them out.

I agree I unburnt fuel popping. Just need to figure out which cylinder.

I appreciate everyone’s input. I am old school engine guy.... the new electronic motors are a different beast for me.

[Timberline]

Wanted to follow up on what I found. Pulled plugs all looked good except #8 it was black swapped it with #2 appeared to clean up a little but still a dead plug. Replaced and all is good.