Not sure where this noise is coming from. 12.7 detroit . Century

Viola . This gives me an idea . It came with the truck. So, take it out and purge the hole right? I will try it tomorrow

 

My 2003 Columbia sounded the same on throttle . I took the truck in to have them do a head gasket and head work . In putting everything together , they found out I needed an intake because the old one was warped . Havnt driven that truck in 3yrs to know if that whistle sound is fixed after changing the intake . That columbia didnt have that yellow air filter monitor gauge but this century does. I will check the gauge in the morning for that whistling sound

 

I sprayed all around there with soapy water while the truck was running . Did you visually see the cut in the boot ?

 

I idled it up to 1300 and started spraying again . I see slight bubbles from the top of the compressor where there are 2 brackets that are bolted to the compressor. The other buble is where the intake (front and towards the air compressor) manifold meets the block. I am thinking gasket or warped intake . The question is ......is this enough suction enough to warrant a hissing noise , because the bubbles are so small and the fuel mileage for 13k in the box is 8.05 mpg off the dash computer .

 

All I can do is retorque the intake bolts and see if it helps. I hate chasing uncertainties .The air filter green / yellow gauge is not leaking, but I will later on take it out and plug is up