Turbo Whistle

[Shawn T]

I have the LB7. I have ridden in a few others and there is a noticable "turbo whistle" at low speeds and upon acceleration. The same goes for the LLY. I can never hear mine. Only when I am in an alley or along side of any object that can reflect the sound, barely. I can feel it spool up on take-offs, because I get that "lunar" take-off at about 2000 RPM's. Should I be able to hear the turbine over the motor? Should it be relatively quite? Would a code pop up if there was a problem with the turbo system, or is it all mechanical? I don't care for the extra noise, but I want the turbo at it's full capabilities. Is this "quiteness" normal, or am I just overreacting? I posted this topic once before and never really got a definate answer.

[R Dogg 56]

I would think that GM designed the Duramax to be a more quieter diesel compared to the Powerstroke and Cummins. The turbo, I'm guessing, is functioning as it should, but not at the decibles that the Powerstroke and Cummins are at.

 

But, then again, I'm no GM-Tech.

[willieboy]

The easiest way to find out is to check he boost. I am sure most any diesel repair shop can do it. I do know that my father's LB7 has a noticable whistle at acceleration. He also has power pretty much from launch, so your "Lunar launching" maybe telling you something as well.

[FinishLine]

[ My truck went in the shop today for the same problem. Same truck too 03' GMC Crew Cab SLT Dmax/Allison 4X4 Carbon Metallic. They have been trying to fix it for 15,000 miles, so I'am not holding my breath until it's fixed. Never throughs a code, But it also has a shut down problem after starting up runs 8-10 seconds then dies wont restart untill you prime the fuel pump. Still waiting for a call back on a download from a black box they gave me to record when i have the turbo problem, It happend 3- times on the way to Reno. No power untill 2200 rpm then takes off to 3200 rpm sometimes alot of whine other times just no powerwhen trying to pass. Will let you know if they find anything.

[Shaners]

I can hear mine on my '05, but I also have the "lunar Launch" that you described... I just figured I have "turbo lag"...

[Timberwolf]

I have an LB7, my dad has an LLY. If you are comparing your turbo whine to an LLY, your LB7 will be quieter. At least mine is ALOT quieter than my dads. By the "lunar" thing it sounds like you may be talking about turbo lag. My dad's LLY also does not have as much lag as my LB7. I think you're fine

[Shawn T]

I have an LB7, my dad has an LLY. If you are comparing your turbo whine to an LLY, your LB7 will be quieter. At least mine is ALOT quieter than my dads. By the "lunar" thing it sounds like you may be talking about turbo lag.  My dad's LLY also does not have as much lag as my LB7.  I think you're fine

 

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Thanks Timberwolf,

I think that is the answer I was looking for. It sounds like the LLY has decreased turbo lag resulting in a higher HP and torque rating. Diesel V8's are sure "dogs" out of the hole.