Stfb

Hi !

I have this strange noise which I don't know if it's coming from the engine itself or nearby accessories (pumps, chain ...).
Here is an MP3 I recorded about this strange noise :
Here the strange sound by clicking here

This happens when the engine is cold (it stays 5min max after cold start and then disappears).
It doesn't stay when I accelerate above 1500r/min and only happens when at idle.

My S2000 is a 2002 with 49 000km.
Forgot to say that my valve clearance has been adjusted at 45 000km.

Is somebody having the same problem ?
Somebody already solved it ?

My Honda dealer said it could come from the oil pump...
Any ideas ?

Thanks a lot for your help ;-)

Slows2k

Check out this thread:

https://www.s2ki.com/forums/index.php?showtopic=242530

Sounds similar to the timing chain tensioner noise. Billman250 has heard more of these than I, Maybe he'll chime in on this one.

Billman250

Took a listen....that is definitely NOT the chain tensioner.

I hate to say it, but do a compression test. If you have high compression in #4 cylinder, you've got troubles. A #4 cyl failure will allow more oil above the compression rings and raise the compression.

You can do a visual by pulling the oil pan, and viewing the clylinder walls from the bottom. Bring the piston up to TDC, and use a long thin penlight to view the cyl wall. The black scoring will be obvious in #4 compared to the rest.

This is a textbook sound...tapping that comes and goes at idle. BUT....#4 cyl tap, in my experience, gets louder as the motor gets hotter. So hopefully this is not the case.

Detroit_Doc

The MP3 might be decieving, but it sounds really "tinny". Sounds like a heat shield to me. Next time it's cold listen from under the car.

Stfb

Thanks a lot Slows2k, billman250 and Detroit_Doc for your quick answers.
I appreciate your help ;-)

Detroit_Doc : I don't think it's a hield shield tapping sound cause it's really like coming from the engine area.
I have modified the sound sample to enhance some frequencies and I lowered the pitch (like you could do slow motion on an image).
You can clearly here the clicks of the valves and that this tap sound is really synchronized with the cycle of the engine.

Listen new sample here

billman250 : thanks for your advice. I will do a compression test.

Squeezer

the s2000 has a noisy valve train from the factory

Stfb

Hi Squeezer !

It's not coming from the upper side of the engine.
Seems to come from bottom.



SOUND FILE UPDATE :
I have modified this sample like the last one (slow motion) :
New sample higher quality

CwestinAP1

I think that I am having the same problem. It is a tapping noise just like in the mp3 clip. The sound comes and goes, but usually can be heard at idle and not at high moving speeds.

Could the tapping sound be a header heatshield? Right now i am only using the top part of the header heatshield with the top 2 bolts. would this cause the noise?

Bump for some help.

Stoner_1

Happened at idle speed huh... I've ben having similar noises but at 4500 RPM. I managed to track it to a loose underbody panel that was clattering around when it reached it's point of "resonance frequency".

If it's not something attached to the engine or routed near it that lose, do the following.

1) Compression check.
2) Check your valve retainers... Make sure they are not receeding or damaged.
3) On your next oil change, run your oil thru a paper towel, and look for anything out of the ordinary. (If you see something shiney, it's bad)

apex2k

Mine has a steady mechanical "clatter" to it (all top side), which I interpret as being perfecly healthy, but that individual tapping in the MP3 makes me cringe.