Chevy and GMC Duramax Diesel Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
47 Posts
Discussion Starter #1
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
 

·
Registered
Joined
·
617 Posts
I believe what your hearing is your turbo. Is it more of a hiss?
 

·
Registered
Joined
·
1,486 Posts
Have someone make you a rumble tune... Its the vanes of your turbo.
 

·
Registered
Joined
·
152 Posts
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.
 

·
Registered
Joined
·
12,050 Posts
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
 

·
Registered
Joined
·
1,609 Posts
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.
 

·
Registered
Joined
·
152 Posts
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.
 

·
Registered
Joined
·
834 Posts
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...
 

·
Stupid Has The Balls
Joined
·
2,515 Posts
You can tune it out or get a good tune that makes it sound like a jet instead of vacuum
 

·
Registered
Joined
·
47 Posts
Discussion Starter #11
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?
 

·
Stupid Has The Balls
Joined
·
2,515 Posts
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
 

·
Its just a worktruck
Joined
·
13,908 Posts
Its a vane sweep test. Yes it will still do it with EFILive unless you tune it out at idle.
 

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

·
Registered
Joined
·
980 Posts
Thats good info!! Good to know
 

·
Registered
Joined
·
129 Posts
i kind of like the Hissing noise, then the turbo gets loud, people look everytime:neener
 
1 - 17 of 17 Posts
Top