if i put a egr valve blocker plate on my truck how will it change the sound? is it going to get rid of that turbo whistle that u hear when the turbo spools down??

Just did mine on Monday, blocker plate & finger stick for the EGR.

No change in sound.

No codes either, so that makes me happy.

It will either get rid of or it will really decrease turbo bark.

Mine still whistles!:ro)

Is it a rattle or whistle?

Since I took out my cat, my turbo makes a rattling noise at low RPM.

Kind of a whistle/rattle. I don't know what to make of it.

It also does it at idle about 10 seconds after I start the truck.

Any ideas?

Gator,
The turbo has a restrictor that helps it warm up when cold. When you start it, it takes a little time for the sensors to sense it is cold, and restrict the exhaust. That is when you get the really loud swishing sound. It can, at times sound like a rattle, but should be a loud swish sound. When the truck warms up, the restrictor is shut off and it quiets down some. Still makes a little noise though. I have gotten used to it now.

Gator,
The turbo has a restrictor that helps it warm up when cold. When you start it, it takes a little time for the sensors to sense it is cold, and restrict the exhaust. That is when you get the really loud swishing sound. It can, at times sound like a rattle, but should be a loud swish sound. When the truck warms up, the restrictor is shut off and it quiets down some. Still makes a little noise though. I have gotten used to it now.

Ok now I need help. Where is this restrictor?

.

Ok now I need help. Where is this restrictor?

.

I dont think there is a restrictor. I think the VVT may go into a more closed position to aid in warm up. I have the extended swish at idle when cold also.

so i have i ??? then.... when i first put my straight pipe onn my truck i heard that swish sound and i was like what the h#$&, so my friend is a GM technision and we put it on a tech to check some other things out at a later date and we noticed that the swishing sound would go away as soon as the egr valve was off and sounded like a diesel should if u ask me... when it was back on the swishing noise was back...so y do u guys say that it wont change the sound

It probably is the turbo changing the pitch and not nessesarily a "restricter". I think the idea is to restrict the exhaust when cold to help in warm up. Which I think it does. This truck seems to warm up better than my LB7 did.

i have no idea if the EGR has anything to do with it or not. I have mine unpluged and it still makes the loud swish when the engine is cold and then it quiets down after it warms up. Not sure how the EGR is coming into play there. I thought the EGR was closed when the engine was cold, and didn't start cycling until up to operating temp? Isn't that right TX Chris?

It probably is the turbo changing the pitch and not nessesarily a "restricter". I think the idea is to restrict the exhaust when cold to help in warm up. Which I think it does. This truck seems to warm up better than my LB7 did.

i have no idea if the EGR has anything to do with it or not. I have mine unpluged and it still makes the loud swish when the engine is cold and then it quiets down after it warms up. Not sure how the EGR is coming into play there. I thought the EGR was closed when the engine was cold, and didn't start cycling until up to operating temp? Isn't that right TX Chris?

You have just described mine also. I am pretty sure my EGR is not in play. :ro) I think the position of the VVT is changed to restrict exhaust at idle to create more heat.

My turbo (Ithink it is the turbo not sure) but at about 1600-1800 RPMs makes a chirping/Tweet type sound. It also makes the same sound when it downshifts for grade braking in tow haul mode for a second or two. Mabey it is just the belt Don't know yet.

i think i know the noise that u guys are talking aobut when the motor is warming up but....i mean the LLY and LB7 soung nuthing alike and i understand that the VVT has alot to do with it but is that all the diff in the sound??? because when the motor is even warmed up the truck doesnt sound like a diesel all u hear is a wooosh sound ....almost sound like it a air leak..hahaha

i think i know the noise that u guys are talking aobut when the motor is warming up but....i mean the LLY and LB7 soung nuthing alike and i understand that the VVT has alot to do with it but is that all the diff in the sound??? because when the motor is even warmed up the truck doesnt sound like a diesel all u hear is a wooosh sound ....almost sound like it a air leak..hahaha

Exactly. There is a V8 rumble if you are near the cab outside, but it is minimal. There is a very big haaaaah at the tailpipe.

so then u are saying that the noise is prlly from the turbo?