ANOTHER Engine Ticking Post
 

Hey everyone,

I am pretty new to the S2000 world, but have already learned so much about this awesome car, especially from S2Ki!

Anyways, I am hearing this ticking noise at idle and just want to see if it sounds normal. 2002 AP1 ~127k miles
YouTube Link:

You Tube

Details on sound:
- It is a light metallic ticking noise, maybe clicking noise?
- Its frequency goes up with RPM
- It sometimes is apparent from a cold start, sometimes it appears when the engine is warmed up.
- You can still hear it with the hood closed
- It is quieter when standing on the intake side, audible from the front, and a little bit louder from the exhaust side.
- If I put my head down behind the front passenger side wheel, it sounds louder.
- Sometimes the tick mysteriously stops for a minute or two
- Sometimes I can hear it at idle ~800 RPM , then blip the throttle to ~1k/1.5k and it goes away until back to idle
- I can hear the tick in the cabin, but cannot hear it after about 3k rpm because of engine noise

Things I've tried:
- Searching around S2Ki for all engine ticking posts, but could find none that really sounded like mine...
- Valve Adjustment (twice)
- Poked around with a mechanics stethoscope (could hear the tick resonating through on some parts, but nothing obvious)
- Tick frequency seems to match individual injector noise, but all of them sounded the same and seemed to be OK
- Disconnect injectors one at a time to see if noise got quieter (no change, same for all)
- Disconnect coils one at a time to see if noise got quieter (no change, same for all)
- Remove serp belt for ~30 seconds (ticking still there)

Possible Causes:
- I don't think common TCT problem, car has GenX Billman TCT from previous owner. Is it possible this is installed incorrectly? Any way to check?
- I'm not good at adjusting valves
- Header is missing engine bracket, maybe this caused an exhaust leak where header mounts to head? Is this bracket necessary? 11941-PCX-000
- Is there a good way to test this other than soapy water when engine is on?
- It is normal injector noise and I am being paranoid (maybe one is on its way out?)
- Normal mechanical valve-train noise (why does it go away sometimes?)
- Other Engine damage?? (hopefully not....)

Next Steps:
- New Plugs (current look OK but are 4 years/10k miles old) - torqued to 25 lb-ft
- New Coils (I have a VERY slight misfire at idle every once in a while when car is hot, no CELs or performance issues) I can hear/feel the puff out the exhaust.
- Remove header and check for leaks
- ????

I know its hard to diagnose a noise from a video, but if anyone can give me any other ideas or items to check, it would be greatly appreciated!!

Thanks!

Likely still a loose valve, nothing serious. The other thing is possible tct related, and again not serious at this level if that's what it is.

Injectors do make a clicking sound when they fire, but that should be consistent.

Oh, let me update: Car does have a Billman GenX TCT on it from Previous Owner.
I plan to do the intake retainers in the next few weeks.. so that means another chance to get the VA right! Thanks!

Checked idler bearing

That engine sounds pretty darn good to me.

No abnormal noises there at all.

Thanks everyone for taking a listen! I'll just keep listening for any change and enjoy the car :)