High pitched squeal/whistle under high boost

Could be something as small as a pinhole in the air to air.
Loose clamp.
Something of that sort.

 

Never run a MaxxForce, just experience from whistling noise under boost

 

Should be around 43psi. Check for exhaust leaks, any signs of soot, can cause a whistle. Rear manifold is a suspect spot. Best bet is to use a smoke machine, every dealer should have one.

 

I get that on my Maxxforce all the time.

Have yet to figure out what it is.

 

I just want to say, I've had my MaxxForce for 3 years now and she's been a good truck.....

IIIFFFFFFF you do regular services and don't idle it.

 

definitely get the spring loaded CAC clamps.