Had my 09 SS for over two years now. In the last year the turbo makes a funny sputtering noise almost like a pressure cooker spitting steam. Its only for the first 20 minutes or so then when it warms up it sounds as it should. And i should add that its only if i give it some boost. Anyone heard of this before?

 

Let the car warm up first. Sounds like you're driving it during the catalytic converter warmup cycle.

 

It even does it in hot weather, after 15 minutes of driving. Seems very strange to me...

 

Are you getting knock? Make sure all your vacuum lines are hooked up too.

 

Nope. No engine knock. Instead of the nice hiss of the turbo i hear a sputter that gets louder as boost increases. But like i said...goes away once engine has been driven for about 20ish minutes

 

sputter out of the exhaust or intake? maybe it could be the bpv screwing up.

 

Hard to say really. Maybe i should just leave it overnight with GM. All i can say is that instead of a nice turbo whistle i get a sputter that sounds like crap and its noticeable outside the vehicle aswell.

 

Strange... sounds like a bad BPV source line. Possibly a vacuum line leak.

 

The noise appers to be coming from right behind the glove box.

 

Right, that's because it's your BPV fluctuating. Need to find out why it's doing that. Should check the lines going to it.

You said it does this for the first 20 minutes right? Are you letting it finish the catalytic warmup cycle? Are you filling with premium fuel(91, 92, 93)?

 

Yes i let it idle for at least 3 minutes before i drive it. Premium in Canada is 91 and yes, its all that i put in it. Never heard knock of any kind. My good buddy has a shop so ill have him check the vacuum lines today and report back!

 

Bpv is what some would call a blow off valve?

 

Bypass valve