Anyone know where to start looking for this, I'll try my best to describe it.

When I initially accelerate (and the car is moving), there's a weird sound for about a second or two, the only way I can think of describing it, is to think of a metal washer on metal bolt spinning really fast.. a high pitched type sound of metal on metal. Its not loud though.

It goes away after about two seconds - I can hear it through most gears. It doesn't do it when the car is standing still and I accelerate.

Any ideas?

 

I wonder too. I hear it and it sounds like the car is F/I. I only hear it at lower rpm, as I guess other engine noise and exhaust noise mask the sound at higher rpm. I have a 2007 so no air pump here.
It seems to match engine speed, so not the diff.

 

No responses?

I also hear it in low range RPM... but mine actually goes away after a 1-2seconds.

 

Do a search...its perfectly normal.

Some kind of harmonic in the throttle body we think

 

What should I search for? :-/

 

Assuming we are thinking of the same sound, I've experienced this too. In fact it happens all the time as long as the car is in motion.

It worried me for a bit when I got my first S2000. After reading information on the Internet, I concluded that it was normal gear whine. I confirmed this (in my own mind) after I installed the AxialFlow shifter. The sound became more pronounced (higher volume) and was otherwise the same -- so that led me to believe it was just drivetrain noise being transmitted to the cabin through the transmission.

 

I'm not to sure if mines the same thing though - it seems to be getting worse - i.e. the sound stays for longer now.

 

Yup - its getting worse... guess I'll book it in.

Sounds a bit like a cricket. Seems to be between 2500-4000rpm.