Godzilla

Annoying "Chirpong" at idle and it really sounds like a belt...but it's not the main belt.

1)As you raise the RPM the noise goes away at about 1800 RPM.

2)Removed the main belt though and the noise was still there.

3) Put a stethoscpe on the engine and it's not a mechanical knock
4) Sounds more pronounced on the driver's side
5) Checked the headers (at the head flange) not an exhaust leak

Krazy98Z28

iTrader: (12)

Is it like metal to metal grind and it comes and goes, its not consistent??? I too am getting the same noise along with a loud tick.

Godzilla

Yes, it started out like that but today became the "chirp" In fact, I gave the initial "ticking" little concern due to the fact that it was not constant and didn't necessarily follow the RPM.

Krazy98Z28

iTrader: (12)

Have you over revved the motor recently, seemed like mine started after i missed a 1-2 shift

Godzilla

Not over revved. I started to hear te noise after removal of the AIR pump and blocked air tubes..

last of the Z28's

start looking into emission solenoids and the such. ive heard some weird noises from this crap on alot of different vehicles. and seeing you have altered part of the system i would give it some consideration. good luck and keep us informed.