Noise on Cold Start-up

hi, I have a 2002 GP GT, and when I start up cold i get a loud noise, like a whisle or a whurling noise similar to a belt slip coming from the intake ducting. I orginaly thought it was the belt, but it is comming from the wrong side of the motor. Oh, and this only happens if the car has been sitting for 2 hr. or more. The noise goes away after a few minutes of driving or idling. I can also get the noise to go away by reving the motor to 3000 rpm and down to idle a few times.

If it helps, my motor/trans have 31000 miles, and it idles at about 1500rpm when cold.

Any suggestions would be greatly apprecated

The idle at start up sounds high. Try cleaning the throttle body (TB) with throttle body or carb spray. The IAC can get carboned up pretty bad. Also, remove the idle air controller (IAC) valve from its seat on the throttle body and clean the spring loaded pintle and the TB seat which has the air orifices. If that doesn't work the the IAC could be bad.

The only other part that comes to mind that could generate a similar noise would be the EGR valve.

Also, check your vacuum lines on the throttle body and intake manifold.

Thanks, im gonna try cleaning the IAT today, and im also gonna replace the PCV valve... I will update tommorow

I took out the PCV valve yesterday, and it was covered in oil, Is this usual? Well anyway i cleaned out the IAC, vaccum lines and throttle plate. The cold idle is now normal, 1000 - 1150 RPM but there is still a noise. You mentoned the EGR valve could cause a noise like this, is that a leaking EGR gasket or something like that.

I took out the PCV valve yesterday, and it was covered in oil, Is this usual? Well anyway i cleaned out the IAC, vaccum lines and throttle plate. The cold idle is now normal, 1000 - 1150 RPM but there is still a noise. You mentoned the EGR valve could cause a noise like this, is that a leaking EGR gasket or something like that.

Oil on the bottom of the PCV valve is normal but not on the top above the small black o-ring. Also, there should be a big orange o-ring to seal the spring loaded plastic part that goes over the PCV valve which holds the MAP sensor.

If the noise is around the EGR valve or from around the throttle body or intake manifold it could be. With engine cold and off you can disconnect the electrical connector to the EGR valve and see if that makes a difference. Then start the engine with the EGR disconnected. The EGR valve is not supposed to be active when engine temperature is less than 167 degrees F.

If EGR is suspected you can remove it by undoing the two 13mm nuts. Clean the spring loaded pintle with carb cleaner and then lube with WD40. Re-install with a new gasket.

Hopefully you do not have any upper intake manifold (UIM) problems. Make sure none of the UIM bolts are loose. Torque value is 89 inch-lbs.