Turbo Gonna Go Boom??

[Turbo Performance]

Stock turbo 05 LLY. When it's cold the turbo whistle isn't smooth (not hot rodding it, just creeping it out of the neighborhood). Best way I can explain it is it makes like a wa-wa-wa-wa-wa whistle sound as you gain RPM and pick up speed. I've tried to get a sound clip but I can't get good enough quality to really hear it. Once the engine is at operating temps, it goes away and the whistle smooths out? Ideas? I checked shaft play a few months back, no in and out, and minimal side to side. Thanks.

Levi

 

[whitetrash21]

Stock turbo 05 LLY. When it's cold the turbo whistle isn't smooth (not hot rodding it, just creeping it out of the neighborhood). Best way I can explain it is it makes like a wa-wa-wa-wa-wa whistle sound as you gain RPM and pick up speed. I've tried to get a sound clip but I can't get good enough quality to really hear it. Once the engine is at operating temps, it goes away and the whistle smooths out? Ideas? I checked shaft play a few months back, no in and out, and minimal side to side. Thanks.

Levi

Mine kinda does the same. Only noticed after the straight pipe and mouth piece went on. Not sure if it's just louder now that all thats done or what. Does it sound like it pulses with the exhaust?? Not a whine, but almost screech??

 

[Turbo Performance]

Well I put a stack in it not long ago and don't remember noticing the noise before then. I'm also straight piped. Stock mouthpiece. I wondered if it was just exhaust pulsing but it only does it when the engine is cold and goes away as it warms up. If it was exhaust pulse I wouldn't think temperature would matter. The turbo has been barked quite a bit, which makes me wonder if it's hurt and when it's cold the clearance is off and it gives me the wa-wa-wa sound. It is kind of a screech I guess, never really thought about it that way.

 

[whitetrash21]

Well I put a stack in it not long ago and don't remember noticing the noise before then. I'm also straight piped. Stock mouthpiece. I wondered if it was just exhaust pulsing but it only does it when the engine is cold and goes away as it warms up. If it was exhaust pulse I wouldn't think temperature would matter. The turbo has been barked quite a bit, which makes me wonder if it's hurt and when it's cold the clearance is off and it gives me the wa-wa-wa sound.

Barked the vnt?? Compressor surge or actually barked to the point of stopping and reversing directions with it?? I thought it was kind of difficult to do that on the vnt trucks.

I know my will surge anytime you back off the skinny pedal at slow speeds, but it does that all the time. Not sure if thats hard on it or not, only seems more noticable now with no muffler/cat.

If you haven't noticed any/minimal shaft play in the turbo, I'm not sure what else it could be. Does the turbo spin freely by hand?? No binding, grinding or catching??

 

[Turbo Performance]

Barked the vnt?? Compressor surge or actually barked to the point of stopping and reversing directions with it?? I thought it was kind of difficult to do that on the vnt trucks.

I know my will surge anytime you back off the skinny pedal at slow speeds, but it does that all the time. Not sure if thats hard on it or not, only seems more noticable now with no muffler/cat.

If you haven't noticed any/minimal shaft play in the turbo, I'm not sure what else it could be. Does the turbo spin freely by hand?? No binding, grinding or catching??

It actually barks, not just the surge because it does that too. I'm going to recheck the shaft play and see how freely it spins. I went to semi-synthetic last oil change and that's when it started to get cold here and I noticed the different sound. I'm wondering if when the oil is cold its grabbing carbon build up on the shaft and the sound I'm hearing is the turbo speeding up and slowing down.

 

[x MadMAX DIESEL]

My turbo barks too, but usually when its cold, or when I let off the trottle quick as my converter is slipping

 

[Redbowties88]

Barked the vnt?? Compressor surge or actually barked to the point of stopping and reversing directions with it?? I thought it was kind of difficult to do that on the vnt trucks.

I know my will surge anytime you back off the skinny pedal at slow speeds, but it does that all the time. Not sure if thats hard on it or not, only seems more noticable now with no muffler/cat.

If you haven't noticed any/minimal shaft play in the turbo, I'm not sure what else it could be. Does the turbo spin freely by hand?? No binding, grinding or catching??

bark/surge/stall all different words for the same thing mine does it too....more often when its cold

 

[JoshH]

Do you have EFILive? Maybe try watching vane position when it makes the noise and when it doesn't make the noise?

 

[Turbo Performance]

Yeah, I have EFI-Live and i considered that. Why would it only do it when cold and not once it warms up? I didn't think ECT effected vane tables...

 

[Redbowties88]

Yeah, I have EFI-Live and i considered that. Why would it only do it when cold and not once it warms up? I didn't think ECT effected vane tables...

oh it definitely does.... specially at low throttle%

 

[Robby Avery]

My LBZ does the same thing your talking about it's the A/C compressor cycling on and off. It only does it when you first start it in the morning and its cool right? Really nothing to worry bout

 

[Redbowties88]

i think you may be confused

 

[TrentNell]

1 thing that could contribute to the cold symptoms is the vains being oil controlled , and the thick oil or different consistancy of oil during warm up is making the vain position" hunt " for the propper spot ?

 

[Redbowties88]

1 thing that could contribute to the cold symptoms is the vains being oil controlled , and the thick oil or different consistancy of oil during warm up is making the vain position" hunt " for the propper spot ?

eh thats good thinking but i would imagine the vane position sensor to be able to accurately read the position well enough for the pressure to be adjusted to get the proper vane positioning no matter how thick the oil long as its getting sufficient flow to adjust....

 

[TrentNell]

eh thats good thinking but i would imagine the vane position sensor to be able to accurately read the position well enough for the pressure to be adjusted to get the proper vane positioning no matter how thick the oil long as its getting sufficient flow to adjust....

I cant answer that question without seeing how the vain control is designed , and knowing if the oil stays the same viscosity during warm up or if it could vary as the oil flows through the vain controller depending on the temp of the oil passing through the vains . It's just a theroy i could be way off .