[SelahPSD]

I have a question for the collective wisdom of the forum. Three weeks ago I bought a 2006 F350 DRW. Yesterday I had a local shop install a MBRP 4" Turboback exhaust system (Straight pipe--no cat and no muffler). When I picked up my truck after the install, everything seemed fine. However, this morning when I started my rig I observed that at idle the sound at the tailpipe sounds like a vaccuum cleaner--the tone is a loud hissing or blowing sound almost like a vacuum cleaner at a DYI car wash! Other than that, the sound and performance seem normal. For example, when I romp on the accelerator, it sounds like you'd expect a V8 to sound--a deep throaty roar.

Question: Is the blowing "vacuum cleaner" sound normal. I've put exhaust system on gassers, but never on a diesel. If it's not normal, any idea what the problem could be? Thanks for any help.

 

[lowrider284]

I have a question for the collective wisdom of the forum. Three weeks ago I bought a 2006 F350 DRW. Yesterday I had a local shop install a MBRP 4" Turboback exhaust system (Straight pipe--no cat and no muffler). When I picked up my truck after the install, everything seemed fine. However, this morning when I started my rig I observed that at idle the sound at the tailpipe sounds like a vaccuum cleaner--the tone is a loud hissing or blowing sound almost like a vacuum cleaner at a DYI car wash! Other than that, the sound and performance seem normal. For example, when I romp on the accelerator, it sounds like you'd expect a V8 to sound--a deep throaty roar.

Question: Is the blowing "vacuum cleaner" sound normal. I've put exhaust system on gassers, but never on a diesel. If it's not normal, any idea what the problem could be? Thanks for any help.

I was in the same situation you were with my 4" system being my first exhaust system on my first diesel. I was also concerned about the vacuum noise at idle and the gasser throaty sound but apparently they are both normal. I always thought my truck sounded different too compared to exhaust videos ive watched.

example:

 

[06_Whitebull]

It is just the turbo whistle. Different turbos have different whistles. Absolutely normal, although I like to think of it as more of a jet sound, not vacuum.

 

[Korx]

Totally normal.

I believe it's due to the vgt turbos, lots of newer trucks do it that have these types of turbos like dmaxs.

Sent from my Autoguide iPhone app

 

[Frankf250]

Mine does it.. Mine also changes idle sound every few seconds. Like it builds up and let's our a burst of air.


Sent from my iPhone using Autoguide.com App

 

[Boudah]

As said above its normal. u basically have a straight pipe and nothing is between the tip and the turbo outlet.. hence the whistle/ whine/ vacuums sound lol

That said... how do u like it because i was thinking about getting one and wasn't sure how loud in the cold it gets? Thanks

-Ellery

 

[Int.Tech04]

the loud "rushing air" or "vacuum" sound is perfectly normal. the vanes on the VGT close at cold start to increase back pressure and warm the engine up faster. with the factory exhaust its there, just not as pronounced as a straight piped truck. when your at operating temp, you'll just get the turbo whistle at idle.

the VGT, or Variable Geometry Turbocharger, is what gives the 6.0 its signature "jet engine" sound, where the 7.3 kinda has that helicopter, chopping air sound. the nice thing about VGT, is almost instant boost off idle, providing excellent pulling power and practically no lag. hell, my truck makes anywhere from .50-.70psi at idle.

 

[SelahPSD]

Thanks to all for your responses. Tyler's explanation makes sense--the first time I heard the new exhaust system the engine was still relatively warm. The next morning when I observed the vacuum/jet sound, the outside air temp was about 34* and my truck had been sitting for 10 hours.

To answer Eller's question about loudness, I think it's perfect! At idle, its only slightly louder than stock in the cab, and its got a great rumble and roar when you step on it. I don't think it's much louder outside the truck at idle, but I can't speak as to how loud it is outside the truck when I step on it.

 

[drunk on diesel]

Mine does it.. Mine also changes idle sound every few seconds. Like it builds up and let's our a burst of air.


Sent from my iPhone using Autoguide.com App

that is a later strategy designed to prevent the VNT turbo from sticking

 

[Int.Tech04]

Thanks to all for your responses. Tyler's explanation makes sense--the first time I heard the new exhaust system the engine was still relatively warm. The next morning when I observed the vacuum/jet sound, the outside air temp was about 34* and my truck had been sitting for 10 hours.

To answer Eller's question about loudness, I think it's perfect! At idle, its only slightly louder than stock in the cab, and its got a great rumble and roar when you step on it. I don't think it's much louder outside the truck at idle, but I can't speak as to how loud it is outside the truck when I step on it.

next time you start the truck from dead cold, crack the window and listen to that V8 rumble it does for the first few seconds before the vanes close. its awesome.