"Whistle" from 4psi to 7psi

[CasterTroy]

6.0
85k miles
EGR delete
straight pipe exhaust
SCT-street

So i have the typical 6.0 sweet sounding whistle and exhaust note. This is NOT it.

I'm towing my 20ft enclosed home from the mountains after a day of riding dirtbikes at Brushy at hiway speeds. 2k rpms 70mpg using cruise on 4 lane empty hiway that goes up and down hills.

When turbo boost is over 7 psi and under load....it's whisper quiet in the cabin. but on flat straights with low load and boost between 4psi and 7psi I hear this slight and consistent "whistle" that does NOT change pitch. but occurs every single time I'm between 4-7 psi

It's kind of irritating...but there doesn't seem to be any effect to the motor or power. I can make this whistle go away with a touch of gas.

70 miles later the whistle is now LOUDER but still only occurs between 4 & 7 psi under mild load and never on deceleration...only acceleration.

After 100 miles it's so loud I can't believe it. and as I pull the truck in the garage at home it sounds like a tornado siren.

What the hell has happened?

[southend]

One of your turbo boots is busted, or the exhaust flex joint is cracked. Not uncommon.

Sent from my SCH-I500

[CasterTroy]

You're exactly right! Passenger side flex has soot around the base and a small spot on the exhaust pipe where it's blowing onto that. Would have never found that without your reply.

Thanks!

[southend]

Originally Posted by CasterTroy

You're exactly right! Passenger side flex has soot around the base and a small spot on the exhaust pipe where it's blowing onto that. Would have never found that without your reply.

Thanks!

Awesome, I been readin these threads, for months. The guys here, well lets just say, I wished I could work with these guys every day. Good people. Glad I could help.:thumbup:

Sent from my SCH-I500

[primetime1267]

Caster, nice looking shortbed dually you got!!

[supercoop71]

My truck just started doing this two days ago. I going home and going to check my flex pipe, with any luck thats all I will find. I thought I was going to have to buy a Turbo. Thanks for the help.

Very helpful web site.

[Snake]

Got beat to the answer, but I'm glad you found it. I had an exhaust leak about a year ago and never in a million years would have guessed the sound I was hearing was caused by the leak I found.