Hi all, been having this issue for quite a while now on my 99 S2000 with 85k. At first I thought replacing the TCT or adjusting the valves would of fixed it but to no joy. Just realising now that the tapping noise is more apparent when the car is under load and especially when cold, then seems to slowly go once warm. Had so many suggestions on what it could be but the fact that the noise is there when under load tells me that a more specific problem could be given. She's also running under bhp and doesn't pull anywhere near the same as my bothers S2000 which tells me it has to be something internal just unsure what.
Any help is much appreciated.

 

Post vid or sound clip. Do a compression and leak down test, do an oil pressure test, this will pretty much tell you what kind of internal problem you have. Check your spark plugs and coils before you go there.

 

How exactly do you check coils? I have wanted to check mine as they have over 130k on them.

 

Thanks for the help. I've been meaning to book in for a comp test, just done it now as I have checked the plugs already. As for the coils a visual check was made but unsure what else to look for if there is? Hoping a comp test will figure it out, if not I'll come back with a video

 

Looking at them, then testing the leads.

 

Well compression came back perfect

 

If your car has perfect compression, and it's down on power then it's likely to be ignition or fuel injection issue. Perform a power balance test, run the car and pull one of the ignition coils at a time for a few seconds. The rpms should drop every time you pull a coil, if it doesn't then it means that cylinder isn't contributing as much as the others. Either a bad coil or a partly clogged fuel injector.

 

Hope this video can be viewed? Ignore the oil around the cover, I had the cover off prior to the video. As you can tell the noise is more towards the exhaust side

http://s703.photobucket.com/user/jud...9550A.mp4.html

 

Does Sound like a valve train issue,
i would recheck and inspect
+ also the roller rockers and inspect spring retainers and collets
could disconnect an injector one at a time

 

It could be valve train, but it could also be an exhaust heat shield. Then again it could also be a partly clogged injector.