b18c1 (Integra GSR engine) sound at idle!

Hi! My b18c1 engine, from my 1999 Integra GSR, is making an odd sound at idle. This has been occurring ever since I did an engine and transmission refresh about 2 years ago. It only makes the sound at idle and what’s even more odd is that IT GOES AWAY when I turn my headlights on (or whenever there’s more electrical load on the engine, such as turning heater/fan on high). My first guesses were vacuum leak or maybe cam gears needing to be adjusted after decking the block significantly (to prepare for new head gasket). I am unable to find any specific vacuum leak and also believe the idle wouldn’t be as stable/smooth if it was this…right? It’s idling perfect at 750+/- RPM. Additionally, the power is all there – the engine performance is better than when I bought the car 8 years ago (prior to all the maintenance I did). I did also put some Skunk2 adjustable cam gears on it, just because I wondered if my theory that maybe the block was decked enough that cam timing needed to be advanced to accommodate that. Only other thing I can think of is maybe a headgasket leak? Any thoughts? No oil in my coolant or vice versa, though. Doesn’t smoke particularly bad, either. Kind of at a loss here…

Side Note: I did a compression test on it a while back. I can’t remember the exact results but I think the cylinders were all pretty similar. Can do another if it’s believed that most likely this is compression loss in 1 (or more) cylinders..but if that was the case, then why would the sound go away when headlights turn on? That is what is confusing me the most.

What I mean by ‘engine refresh’ – New cam seals, new distributor seal, decked block, new head gasket, new valve stem seals (intake and exhaust), valves lapped, new valve cover seal, new spark plug cylinder seals (as part of valve cover gasket seal kit), new intake manifold gasket, new exhaust manifold gasket, new PCV valve, etc.

Here’s a link to a YouTube short I posted where you can hear the video – https://youtube.com/shorts/09A4Rg5E1Mc?feature=share

Note: You can hear the sound with headphones on or if you have external computer speakers. Sound is not that audible when you have just smartphone speakers or built in laptop speakers.

Resubmitting this because I don’t see it anywhere on the forum?

Topic

[IsaacParticipant]

Things I’ve already tried (in addition to what was done during engine refresh):
I’ve checked for vacuum leaks and am unable to find any
I’ve made sure that all the vacuum lines are connected to the right source, after putting everything back together (after refresh)
I’ve made sure mechanical timing is correct
I’ve made sure ignition timing is correct
I’ve tried cam gears adjusted at 0 degrees (TDC)
I’ve tried adjusting cam gears to 2 degrees advanced (could go more if we think that it could help)
I’ve ran a compression test (as previously mentioned, can’t remember the exact numbers but I think they were relatively similar across all cylinders)
I’ve checked for misfires by removing each ignition wire, from each cylinder individually (1-by-1)
I’ve cleaned my Idle Air Control Valve screen (didn’t think it was related, but figured it couldn’t hurt)
I’ve cleaned the intake filter (didn’t think it was related, but figured it couldn’t hurt)

[Author]

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