Hopefully someone can help. I was driving my balt pretty hard the other day and at wot something happened. I didn't hear much of any noise, but all of a sudden the car dropped out of boost and would not boost after that. A friend was driving behind me and said he saw a puff of black smoke come out of the tail pipe. Shortly afterwards the CEL came on and showed P0299, turbo underboost, and P0030, O2 sensor issue I believe. So I took it into the dealer yesterday and they replaced the O2 sensor. CEL is now off but still no boost. So they have been looking at it today and have told me they have no idea what's wrong. They've done pressure tests to make sure there's no leaks and have checked the tsb for the wastegate. Any ideas?

The car runs great other than there is NO boost. I can't even hardly get it to 0 on the gauge. I'm worried because the dealer is at a loss! Any ideas are much appreciated!

 

They don't care you're tuned? My dealership doesn't care about anything, but once you're tuned they void your warranty lol.

This I guess is a free bump because I have nothing constructive to contribute. Sorry

 

My tune is stock.

 

This is me thinking out loud but.... If it was black smoke, that is usually from too much fuel. If you were WOT and then your friend saw the smoke, that tells me, yes, obviously it's not getting the air it was supposed to and it was super rich and now, you can't make boost at all. I would first check to see if the turbo even spools. If it does, I would check for cracks or leaks in the pipes starting from the charge pipe to the intake manifold. All the vac lines to the turbo still hooked up and not broken? Maybe the waste gate is stuck...

Excuse my ignorance if this all seems too straight forward. At this point I'm still new to the Cobalt. Ive only had mine a month and haven't turned a wrench on it... Yet...

 

Sounds logical to me, but to pick your brain a little more, I'd like to learn from this.

I geared most of my mods to address the weak parts of the cobalt. Busting CPs, IC end tanks, stuck BPV, etc.

So my question is this, what would cause something like this and how is it prevented?

 

I don't have enough experience with this vehicle yet to answer this question with confidence. There could be myriad things that could cause this. My limited experience tells me that if the car is running just fine in "N/A Mode" it has to be something with the turbo. What caused it, I really don't know.

 

Check your ic endcaps.

 

A big leak was my first thought, but the dealer said they "smoke" checked the entire system and couldn't find any leaks.

Good thoughts so far. I'm leaning towards wastegate like Frogstofall said.

 

Well they found the problem.

http://www.facebook.com/media/set/?s...ab4fd47&type=1


Looks like I'm getting a new turbo.

 

Your link isn't working for me.... What happened exactly?

 

turbine blade on the exhaust side blew up. a big chunk is missing and several of the individual blades are damaged. I'll try to fix the link.

Link should be working now.

 

Same no working link

 

Wow..... Did they say what might have caused this?

 

No. They said they haven't ever seen anything like this. I know I was pushing the car pretty hard, but I think there was a small defect in my particular turbine blade that finally gave out.

I just had a scary thought. Anyone think it's possible/probable that something was sucked out the exhaust and slammed into the turbine blades? Like maybe an exhaust valve?

 

Wow.

 

Yeah. That's what I said! Wow!

FYI So far the dealer has been really good about it. I've answered all of their questions which so far have only been trying to help figure out the problem based on how I was driving when it happened, WOT, any noises I heard, etc. They haven't questioned any aftermarket parts (i.e. intake, engine mounts). Not that those things would cause this, but some dealers would try to blame it on them. They have not even alluded to any abuse or overagressive driving. We'll see if they have more questions for me once they get GM involved. I'll keep you all updated just in case you're curious.

 

You have stock cat so the big missing chunk of blade and anything else is lodged in the cat only place it could go.

 

They just told me that the new turbo would arrive on Friday, so I may have my car back as soon as Friday afternoon.

I asked them about the exhaust and they said they recovered the pieces from inside the turbo and the exhaust was not damaged. There has to be some pieces that are lodged inside the cat though. Good excuse to get a new dp with high flow cat! Lol