I think I found the cylinder that is not running optimally - ZR-1 Net Registry Forums

tokuzumi · 07-05-2022

No SES light, but the car definitely wasn't running optimally in the low RPM range. Pulled the plugs on the driver's side. Cylinder 5 (assuming driver's side front to rear is 1/3/5/7) was coated in oil on the threads...no oil pooled in the socket.

Most of you probably know already, but the LS based engines use the same size plug as the LT5, so I swapped out that plug. Gap was significantly smaller than the others. Didn't appear to be mechanically gapped, so I don't think there was any piston contact.

Need to check the passenger plugs, and will use the rest of my NGKs to do a halfway tune up. I won't replace wires or coils for now.PXL_20220705_235729766.jpg IPC_2022-07-05.20.02.42.2530.jpg

Sent from my Pixel 3 using ZR-1 Net Registry mobile app

07-05-2022	#1
tokuzumi Join Date: Jun 2022 Location: Alpharetta Posts: 28	I think I found the cylinder that is not running optimally No SES light, but the car definitely wasn't running optimally in the low RPM range. Pulled the plugs on the driver's side. Cylinder 5 (assuming driver's side front to rear is 1/3/5/7) was coated in oil on the threads...no oil pooled in the socket. Most of you probably know already, but the LS based engines use the same size plug as the LT5, so I swapped out that plug. Gap was significantly smaller than the others. Didn't appear to be mechanically gapped, so I don't think there was any piston contact. Need to check the passenger plugs, and will use the rest of my NGKs to do a halfway tune up. I won't replace wires or coils for now.PXL_20220705_235729766.jpg IPC_2022-07-05.20.02.42.2530.jpg Sent from my Pixel 3 using ZR-1 Net Registry mobile app