I have noticed that when I am decelerating I hear a high pitched almost siren like sound coming from the engine bay. Also, when cruising around at 3K rpm, if I let off the pedal I hear a slight whoo-whoo-whoo sound coming from he rear end. Are either or both of these sounds normal?

 

you did not say whether the top was up or not...
top up those sound like pretty normal noises- i suggest that you go to a local meet and check out another car- or have another owner check it out (or take it to your dealer... my least favorite choice- unless you cant find other owners!!- cant tell from your avatar where you are, so cant help you any more than that)
top down you should pretty much just hear the engine and the sound system!

 

differential whine

 

The top is up when I hear this although if I am cruising in 2nd gear at 30mph or so I can hear it sometimes too. The sound isn't very loud or anything, it is real faint.

I am in Abilene Tx.

 

woops, just noticed that you are new here!
let me back up and mind my manners:
welcome to the car and to the board!!

from the main page you can find the north texas forum on this board- i would post up your question so see if there are any meets coming up (where you can meet other owners in your area)- or whether another owner would go for a ride with you to listen to your noises... to see if they are normal or should be looked at.
it does sound like your tranny and diff (as v9. mentions)- but without being there, cant tell if its a normal noise or not-

 

this is most likely normal...happens around 3-4K RPM

 

Yes, is the S2000 decceleratin' sound... LOL...

I love to call it:

GRRRUUUUUUUUUUUUUUUUUUUUUUUUUUUUUuuuuuuu

 

i thought the noise was for ap1 only?
ap2 has it, huh?

 

yup...and it's very hard to describe in words
i once heard someone describe it as a marble going around inside a tin can......i guess it kinda sounds like that.

 

My car has a "very" light, high pitched sound that, for me, appears to be coming from the engine compartment. I only notice it when I'm accelerating easily in the lower three gears. Accelerate harder or, once you're fast enough to be in the upper three gears, it's not noticable any more. My impression is that it's something like a cam chain whine as the sound definitely raises and lowers in pitch with engine speed. It doesn't bother me.

My car also has a very noticable exhaust harmonic at steady speeds with engine rpm between 3000 and 3500. It's there at 30 to 32 mph in 4th gear, just over 60 mph in 6th gear, or any other gear that has the car in the right rpm range. I kind of like it!

Drive Safe,
Steve R.