Exhaust Hissing Noise

[KeepinItFord]

Why does my 6.0 have a hissing noise coming out of the exhaust, last night I put on a 3.5in DP n the cat delete pipe on and just ran it like that because the rest of my exhaust isn't here yet and at idle it hisses almost as loud as my turbo whistle, why is this?

Thanks Guys

[Acidsniper]

Sounds to me like you're hearing your true exhaust for the first time haha.

You gotta remember prior to an exhaust installation you had a cat and muffler in there to baffle the noise as well as reduce the overall flow of the exhaust. My guess is the noise you're hearing is normal but it's hard to judge without a video / audio example of what you're hearing.

[KeepinItFord]

Powerstroke.org is still as fast as I remember, come on guys! I'm to lazy to use the search function!

[KeepinItFord]

I'll get an audio clip tonight, it doesn't sound like an exhaust it sounds like crap, haha..

I would say it's as annoying as the 7.3s exhaust valve

[Acidsniper]

Yup... Perfectly normal

Exhaust Hiss
6.0 hiss
tailpipe hiss

I know my truck with a 5" MBRP setup makes it sound like I'm back in the Navy standing next to an F-18 engine haha.

[KeepinItFord]

Where'd u get the 5in DP? I was looking for one but couldn't find one

[Acidsniper]

I don't think there is one... From what I remember even the MBRP 5" turbo back is still a 4" downpipe from the turbo going up to a 5". MBRP site is down for me right now so I can't double check that right now.

[KeepinItFord]

It's down for me too . , but all the 4" I see are for autotrans only? Whats the difference?

[Evil Eye]

Originally Posted by Acidsniper

Yup... Perfectly normal

Exhaust Hiss
6.0 hiss
tailpipe hiss

I know my truck with a 5" MBRP setup makes it sound like I'm back in the Navy standing next to an F-18 engine haha.

That must really suck to be you... Does it piss a bunch of hydraulic fluid all over like those Hornets used to do? (I spent 4 years on the USS Abraham Lincoln).

[BB Wolf 63627]

I too removed my muff this week. Sound at idle is almost annoying. But boy does it sound good around 13 pounds of boost. Also I have seen a 150 - 200 degree drop in my EGT at interstate seed.I believe it is a normal sound with cat & muff deleted.