53 people looked and only 1 responce. Come on guy's...AT least this is a NEW question. 04 6.0 F350…57,581ml…Just put on the MBRP 4” CAT back…Kitty’s leaving soon. Anyway, at start up, I get great sound from the muffler then I hear a small short squeak from under the hood and the sound from the exhaust cuts in half. You almost can’t hear it. Truck runs great but I get that squeak every time I start it. Any idea’s???

 

You sure it's not the turbo whislte. The truck should sound loud when youturn it on then get quite. When the turbo starts working

 

If you were to post up a video of the sound MAYBE then someone could help.

 

well i may not have a answer but some info helpful probaly not but here. I did a 40 dollar exhuast system. yep. had a shop remove muffler and fab a pipe of same size and material to fill void. then i removed cat at home and gutted. reinstalled. The truck is not that loud as one may think. It sounds really good. The turbo is really noticable. I dont have any actual facts but it seems the turbo spools with ease now. To the sound thing at idle cold or at hot i can hear fluctuations like a valve or something cycling on or off?? When under acceleration there are times where the exhuast tone is almost quiter than stock now take in mind all i have is pipe no nothing so i belive it is just pure harmonics of different engine speeds amount of gas passing thru turbo etc etc... I truely love my truck but have 4 kids and on a real budget. if i had the money i would get the same exhaust you have gotten. I personaly would not be to concered. If it was mine i would do a good look over of everything to make sure there was nothing my common sense could tell was wrong. I do know now that these trucks must not have much back press or my wife would of kicked my *** for my 40 dollar exhuast..lol

 

Mine makes a squeak on start-up too. It only does it when cold.

 

mine doesn't make a squeak but i do know that when you first start up your truck your turbo veins are in default position which gives you that cool sound. shortly after you start it up the veins move and that is what makes your exhaust quiet down. you should still hear the whistle and what sounds like someone opening their throat and breathing out.

i have the same exhaust you do only my kitty has been killed already so yours may not be quite as loud as mine does but not by much.

 

Mine squeaked until the unisome ring finally stuck. They removed the turbo, replaced the unisome ring and put high temp antisieze on it and all is good again. If you truck sits for long periods of time then you probably have rust built up around the unisome ring. Driving it like you stole it might get things loosened up again.

 

Not sure what the squeak is. It might be your waste gate

 

This is straight off the Banks webs sight

Let’s begin by describing what a turbo wastegate is. A wastegate is essentially a device that bypasses some exhaust flow around the turbine section of a turbocharger to control maximum boost. A wastegate is usually controlled by a pressure actuator that is connected to manifold pressure. The wastegate is normally closed, held shut by a spring inside the actuator canister. When preset pressure limits are exceeded, the actuator progressively opens the wastegate, allowing exhaust flow to bypass the turbine, thus regulating manifold boost pressure. On the surface, it sounds like a simple premise, and in fact, a wastegate is a simple device. The problem comes from the pressure in the exhaust system, called turbine inlet pressure that can bear against the valve, overpowering the spring in the actuator, and forcing the wastegate open at lower than intended boost levels.

Original equipment turbocharger wastegate actuators are selected or engineered for a specified boost level and turbine inlet pressure. To keep costs down, such actuators are usually just big enough to do the job at the stock boost levels. If the turbocharger boost is increased for additional airflow and performance, the stock wastegate actuator is frequently incapable of holding the wastegate fully closed until the higher boost level is reached. This happens because turbine inlet pressure also increases as boost pressure rises. The fix is to use a bigger spring in the wastegate actuator to hold it closed until the desired peak boost is achieved, however, that also requires a bigger actuator diaphragm to override the heavier spring when the desired boost level is reached. That’s why Banks created the Big Head actuator that’s used on many of its diesel power systems.

The net affect is that the turbocharger comes up to peak boost more quickly and then maintains that boost level throughout the engine’s RPM range for optimum mid-range torque and top end performance.

 

There is no wast gate on a 6.0 unless you have an am turbo. These are vgt turbos

 

Why are we even talking about waste gates, these trucks are not equipped with them.

 

Didnt relize which thread I was in sorry for the confusion