Engine/Transmission (1994 - 1998) new noise after upgrades

[datablitz]

after installing my AFE air filter and boost elbow, when the truck isnt fully warm, if i step on the throttle, and let off quickly there is a hissing/shuddering noise that seems to come from the intake... .

just wondering what that noise is... any one know?



Thanks

 

[csevers]

I'll take a guess that it is the turbo!? the AFE intake opens up the air flow a lot witch comes with more noise. Your going to hear a lot more turbo music from now on.



Craig

 

[datablitz]

well, yes i hear the turbo on accelleration, and driving at 60mph, but i am talking about a sound like air is comming back out of the intake, and it shudders/chatters... it very well could be the turbo, but i was looking for an explanation as to why it makes that nosie.



Thanks

 

[LHartman]

Turbo bark or "huffing" will happen if you put your foot in it and let off quickly.

 

[TravisG]

Huffed it.

I agree with Mr. Hartman. I just got a scotty two, and the first time it happened I about crapped my pants.

 

[datablitz]

so, is the bark a problem? what is the cause?

 

[TravisG]

When you let off the throttle the air going through the turbo is forced back the other way. Causing the impeller (I guess that is what you call it) to spin the other way. That is what causes the bark or the huff as you described it. Barking a turbo can break a shaft I have heard, but I have also heard that the stock 35s are pretty tuff, and will take a pretty good beating. Maybe someone that has a little more knowledge can chime in here, and elaborate a little more. This is just what I can remember the first time I "barked" a turbo.

 

[krs]

When my throttle snaps closed, there is a brief whoosh or whistle sound from the air filter area. What is causing this?



"When the engine is loaded, very high turbine speeds are required for the turbo charger to provide intake manifold boost. When the fuel is suddenly cut off, the exhaust volume collapses and the turbocharger rapidly spins down. As the turbine looses speed, it looses it's ability to sustain the manifold pressure and compressed air rushes backward from the manifold and through the turbocharger. The momentary airflow reversal is not harmful and produces the short pSSHTT sound. "



http://dodgeram.org/tech/dsl/FAQ/turbo_faq.htm

 

[datablitz]

well, the huffing in my turbo seems to be getting worse, and does it warm or cold, and at only 10psi, if i let off the throttle, it will "huff, or bark, or shudder about 3 times, is this something i should be concerned about? is it related to my AFE or the adjustable elbow i got from tst?

should i put the stock elbow back in? i would rather have a nice hissing sound than this sound...

 

[JoeBioDiesel]

datablitz,

The noise was almost certainly always there. You just hear it now with the new air filter housing. It's like removing the exhaust muffler and thinking the engine got louder. The engine isn't making more noise, you just hear it more.

Plenty of turbo vehicles do it. The more boost they make the more shudder they make when defueling.



Joe

 

[britannic]

Your noise is music to a performance diesel trucker's ears, but for the "Passed and Curious" boy racer, it would be a harbinger of doom, because turbo gas engines need a blow off valve to vent the sudden boost pressure rise when the throttle plate is snapped shut. If the blow off valve on a gas engine fails in the closed position, the sudden turbo stall can result in expensive damage.



I saw an advert that made me laugh the other day; it was for a simulated blow off valve sound simulator that could be installed under the hood of a non-turbo car LOL !

 

[datablitz]

yea, i had of couple guys that work on cars tell me i should put a blow-off valve on it

 

[britannic]

Now you can take the money you saved on not taking their advice and spending it on your next power upgrade !

Originally posted by datablitz

yea, i had of couple guys that work on cars tell me i should put a blow-off valve on it

 

[datablitz]

actually, i have to save up for a while for the next mod..... ATS stage IV