While it may not hurt performance it is definitely NOT normal. Anything like that I would replace. Conversely, some aftermarket boost controllers make that sound which is normal.

I wonder if anyone else who's tuned is experiencing this noise? I guess it could be a result of trying to make more boost than it was originally intended for....

 

I'm not tuned at all. Bone stock.

 

I thought mine only did it with my tune on but I was doing it on my way home today with it off and it would start after about 8psi

 

Not at all. All LNF will experience this noise at some point. It is in inevitable.

ok here is a picture. NOW this is not the turbo off the LNF. But it is the EXACT same



Now in the red is a Rivet that holds the "round piece" to the lever the lifts when the wastegate actuator says "open"
Over time that turbo get really really hot. we all know this. And what happens when metal gets hot? It expands. Do this over and over again with metal and it will deform. This is your standard rivet. Nothing special.
Now see where the yellow is? thats the area that becomes loose and thats where the rattel comes from.
So basically what happens is the rivet gets expanded when its hot and gets deformed, not holding the 2 pieces together as tightly as they originally were. so as the air rushes past the wastegate the piece wobbles and creates said noise.
When the turbo gets to "x" temperature the sound goes away because all the components hto and expanded and everything is "tight" once again.

 

So basically it's wearing out. I'll stick to my statement as that would drive me absolutely bonkers. Good to hear that it can go away once warm though.

 

Makes sense. Thanks. I might just try and get a new turbo anyway if the dealer is willing to do it.

 

It would be cool if some could machine the gate as a whole and not use a rivet at all .

 

Yep thats the noise.

Except mine is not quite that noticeable.

Looks like I purchased the exhaust gaskets for nothing!! Damn.

Thanks for all the info, I would have never guess that was the source of the noise.

My car is also bone stock except for an intake.

 

Good Ill let my dealer know and hopefully get it replaced.

 

See the thing is it wont get replaced. Because the next one will do it over time. and its not a part that u can just swap off the turbo. GM will have to replace the WHOLE turbo.

 

Thats fine by me. Thats why I bought a new car I love using that warranty

 

Your going to waste GM dollars because the sound is annoying???????? Good thing i shared the information with my local dealer and they sent it up. Hopefully there will be a TSB on it so they dont waste hundreds trying to DIAG your car when there isnt a problem with the functionality of it.

 

Gm Dollars? lol they should make a better part in the first place. It might be a Cobalt but it has enough rattles as it is... Thanks for your help

 

I was thinking the same thing.

Its not worth throwing away a perfectly good turbo and having GM pay for a new one because of an inherent design flaw that creates a slightly objectionable noise only when under boost.

I'd prefer not to have the noise of course, but of the replacement turbos are the same as the current ones, there is no point in trying to get it replaced.

And if you ever see how a flat rate tech works when doing warranty work, you may want to live with the noise anyway. The less experienced guys never seem to get the car back together the way it should be.

 

Your a god damn retard. GM didnt make the part you fool. its a BorgeWarner turbo. Educate yourself before you open your mouth.

 

I dont give a **** go **** yourself douche bag. I didnt ask for your opinion

 

Right..... I'm the douchebag.......... Thats how you treat people who give you an answer to your question?

Also a respected member of this community?

Learn your place on this site and respect people who are more knowledgeable then you. Because when you actually have a real problem. No one will answer you

 

Actually I said thanks and then you begin to lecture me. STFU and go away. There is a search button which has this magical place where just about everything has been asked. Go get laid or something and get off your high horse

 

Its not even made by GM.

Give it a rest.

When ZZP releases the new Borg Warner EFR Series bolt on turbos, its a great reason to upgrade.

 

Get off my high horse? why because i told you that GM didnt make the part?

And ur a typical e-thug. going for generic insults.... Go get laid??? haha your pathetic sir

 

e-thug?? Wow. and no its because you presume to tell others what they should or shouldnt do based on your own opinions. I dont give a **** who makes what. All I know is that GM will replace it and if that one goes bad Ill get another. If they cant install, build whatever a decent part that wont at least make it to the end of the warranty then they should replace it no matter if it is annoying or what. So please do me a favor and jump off a cliff or something.

 

jump off a cliff......... Hahaha it gets better and better

 

Seriously...just stop posting.

You sound like you're 14 years old. You need to chill out and grow up.

 

Agreed!

 

Ill be honest, I'm with him. It's absolutely absurd to suggest that I should have to listen to a loud ass annoying ticking sound after I just shelled over $20k+ on a new car with a warranty. If GM is gonna offer warranties on the parts that they use on their car, then they better damn well expect me to make use of it. GM is a multiple billion dollar company. I can GUARANTEE paying a mechanic to replace or repair these turbos under warranty (which actually most likely comes from Borg Warner) ain't gonna hurt the bank.

NO ONE should feel guilty for making use of their warranty. Perhaps GM will learn and in turn BW will learn that they need to make better internal wastegates.