[thedoc]

Just wondering if others are experiencing this. I know at first start up the exhaust makes funny noise for couple seconds then goes into deeper rumble. What exactly is changing anyway?
Also as I approach a stop sign then finally stop, my exhaust will change to higher pitch for couple seconds and then back to deeper rumble. Then other day while idling in parking lot I walk around to open tailgate and the thing makes the same hissing noise that it does at initial start up for couple seconds then goes away. I hate that different noise. Anyway to get rid of it?
thanks

 

[gossfam]

I believe what your hearing is your turbo. Is it more of a hiss?

 

[Kroggs]

Have someone make you a rumble tune... Its the vanes of your turbo.

 

[triton220lts]

Just wondering if others are experiencing this. I know at first start up the exhaust makes funny noise for couple seconds then goes into deeper rumble. What exactly is changing anyway?
Also as I approach a stop sign then finally stop, my exhaust will change to higher pitch for couple seconds and then back to deeper rumble. Then other day while idling in parking lot I walk around to open tailgate and the thing makes the same hissing noise that it does at initial start up for couple seconds then goes away. I hate that different noise. Anyway to get rid of it?
thanks

I've been wondering what this was also.

 

[kman2468]

yes it is your veins opening and closing..it sucks lol sounds like a vaccum u need EFI or edge evo to have it be gone

 

[lubeman1969]

Definately the turbo vanes changing position. When you hear the rumble, they are more open. Hiss, they are more closed to help build boost. Open lets the egt's drop a bit faster.

 

[triton220lts]

yes it is your veins opening and closing..it sucks lol sounds like a vaccum u need EFI or edge evo to have it be gone

Mine has edge evo race but still does it.

 

[kman2468]

Mine has edge evo race but still does it.

i thought the edge tuned it out of there?

 

[DiRtY 09 MaX]

it does tune it out just some random times it will open and close causing it to hiss and then go back to rumble...its normal well atleast mine and a handfull of other buddys trucks do it also...

 

[Odyssey25013]

You can tune it out or get a good tune that makes it sound like a jet instead of vacuum

 

[thedoc]

Appreciate the info. I guess its normal but I do have the edge evo race but it still periodically will make that hiss noise. Very noticeable with different exhaust. I get people saying what the hell was that noise then I try to explain and they give me some crap about it being a chevy thing. Does EFI Live do the same thing?

 

[Odyssey25013]

When the truck first starts up it will almost always change the vane position. I don't know if its a self test or something but you will get the hiss rumble hiss. Just a normal thing

 

[DMAXchris]

Its a vane sweep test. Yes it will still do it with EFILive unless you tune it out at idle.

 

[FREIGHTTRAIN]

there is your answers yep its the vanes

 

[darkcherry08]

yep!! Mine does the same thing,it will hiss and then have a rumble for a few seconds and then back to the hissing..

 

[darkcherry08]

Thats good info!! Good to know

 

[AMA D-MAX]

i kind of like the Hissing noise, then the turbo gets loud, people look everytime:neener