Any help here would be much appreciated!...have an 01 f350 powerstoke(4x4,CC,SB,6 spd.)...i put a chip,4inch exhaust(from turbo)4 inch lift,and a K@N filter.The trucks turbo whistle obviously got louder with the K@N installed.Recently i noticed the whistle has gotten noticeably louder.I was worried that maybe my turbo was starting to go(only 180,000 km...and babied mileage..truck not "abused").So i took off intake side of turbo,so as to have alook at the vanes.They are what i would describe as some wear on what i would believe to be the leading edge of the fins,more a discoloration in the metal more than anything..no real signs of pitting or anything that i could see...and when i grabbed the vanes,i tried to move them up and down,and back and forth,in case i could notice some play in there(like maybe bad bearings?)and it all felt tight.The truck runs as normal,no loss of power,the whistle is just louder,so i hear it more often...and i don't really even necessarily notice it under heavy boost,like when i hammer down on the pedal..it's actually seemingly more noticeable at lower RPM's and when i let off on the throttle..it's kinda hard to explain really...but i know something is not right..i was thinking maybe an air leak somewhere(like the red flex hoses to the intake manifold )...but i haven't been able to find anything yet...a list of some stuff that it could be,and stuff i should check would be great...thank you very much.....Brent M

 

Same thing happened to me years ago on my diesel... I put the stock filter back in and the whistle was back to normal. I think its something you have to live with when you change filters. I also had a load whistle on a gas engine with aftermarket kit. I only run stock filters now since aftermarket isn't all its cracked up to be.

 

I have an 08 6.4l and recently had a cracked inlet pipe that caused the engine to sound like a teapot going off at relatively low rpms (2-2.5k) and about 20lbs of boost. It went away as the rpms increased and did go away when i backed off the gas.

 

i have had the k@n for a couple of years,and it definately made the whistle louder...but this has just started to happen a few days ago..this "new" whistle is different..definately louder.

 

the "inlet pipe" idea does make some sense....sounds very similar to what iam experiencing...i will look at that for sure...by inlet pipe,i imagine that refers to the pipe leading into the turbo?....thanks for any and all suggestions.....don't like knowing something is wrong and not knowing what it is....drives me nuts!

 

Yes, the pipe leading into the turbo. My right side inlet pipe was cracked (so apparently there are two).

They had to drop the transmission to gain access to remove/replace the part. It took them more than a day to complete the job.