When I start the car cold, and after a couple of minutes to warm up the engine, this noise thats sounds a high pitched whistle comes from the engine bay, loudly at first then fades into a whisper and then disapears. Just sounds like what the engine does after its warmed up, but just curious if anyone else has this noise.

 

One more thing, what is it that makes that noise? Never heard it on any of my other Hondas before.

 

Have you installed a header? Sounds like an air leak.

 

Do this: when it first starts up and then you hear this noise, if you run your engine up a little bit, does it stop? And then let out on the accelerator and it starts up again?

Chances are it's the Secondary Pulsed Intake Pump... It's used to feed extra air to the engine in the interest of warming the cat more quickly and thereby reducing emissions more quickly. Or something along those lines. It's mounted in front of the front left wheel behind the bumper cover.

It's an innovation unique to the S2000 (as far as the Honda lineup goes, at least)...

It usually turns off within a minute, as soon as the engine has warmed sufficiently.

- Chris

 

Yeah, after a few minutes it turns off, so I guess there really isn't much to worry about then. Just curious as to what that noise was though. Thanks guys.

 

Mine does it. I think it's normal. I really hear it when I'm parked in the garage and I start it cold.

 

Sorry, I never noticed it.

 

That is the sound of the pre-heaters for the Cats - how do you think the S2000 gets LEV status? The 00 NSX's have that too whereas the prior models did not. It is more noticeable in the S2000 because of the minimal sound insulation.

 

I have that noise too. I think it sounds kinda cool, like a jet engine warming up or something.

At one of the meets, I noticed that everyone that turned on their engine had the same sound.

 

No, No its the little supercharger, you don't really think they get 240BHp from a naturally aspirated 2.0 engine!