very first:
Here are two videos clips of my problem
Details:
-I fully rebuild this engine. I used a 22re performance head and bought the rebuild kit from them as well.
-What else is new? Fuel pump, fuel filter, injector orings, all the gaskets, idle screw oring, brake master cylinder, power steering pump, all pulleys, ac compressor, belts, starter, clutch, throw out bearing, pilot bearing. Almost everything.

Other information:
-This only happens after the engine is warm. On a cold start I have zero issues and no whistling
-Other than the annoying noise the engine seems to behave. After warm, slightly pressing the brake will cause the idle to pulse between 500-1000 rpm.
-EGR is deleted

What I’ve done:
-I suspect this is a vacuum leak. I think the brake pulsing is related and hints to this. I double checked the torque on all intake hardware. Seems like the sound comes from under the lower intake.
-I isolated the plenum and disconnected all vacuum lines. The whistle persists.

I plan on completely redoing the intake after finals next week. I am a little confused, if the seal from the intake to the head was not done right why does it only whistles when warm….

 

It's definitely rpm related as it slowly dies when you shut of the engine. Buy one of those inexpensive auto stethoscope and listen to every components to isolate it. I hate unwanted noise, Good luck.

 

Spray some water around all the vacuum related components.

 

Did a full resurface and reseal of the lower intake manifold. Whistle is gone!