Alright guys, just got through racing a MS 3 and during the race when I went to switch into 4th I think I just felt the car jerk a little and power just dropped off. Afterwards, when trying to figure out what happened, I couldn't get the car to boost past 5psi, which I am assuming is limp mode and I have had no problems up until this point.

Mods on the car include turboback exhaust, K&N Typhoon intake, charge pipes and Trifecta tune.

I got to thinking that maybe the charge pipes had started working their way loose. Checked them out and they look fine and are very snug. Checked everything I knew to check including the intercooler and everything looked good. AFR is still good as well and I mean the car still runs the same, it just doesn't boost past 5psi. I am now thinking that the rubber on my stock BPV could have just cracked. Any ideas?

 

I would double check the lower hot charge pipe again at the intercooler. It can look snug, but still leak a little if it has moved some. I had mine move just slightly, and it did something similar to what you are seeing.

Did you hear any booms or bangs when it did this?

Does the car throw a CEL light or any other messages?

I remember reading about a rod on the turbo that has nut that can loosen too. I am not sure where that is at though.

 

I had the same problem and it was oil on my MAP sensors. Take them out spray them down with MAF cleaner and you should be good. It's sucking oil fromthe PCV valve an shooting it down your charge pipes. Make sure to clean the cold side chrage pipe MAP sensor and the one on the intake manifold. I believe the one that was screwing up my car was the manifold MAP sensor

 

Well I can tell you it's not limp mode. Limp mode will make zero boost and you DIC will display Engine PWR reduced. Sounds like you either sprung a big boost leak or a MAP sensor is shot.

 

Check underneath, theres a nut that connects a rod that opens and closes ur waste gate. That was the problem with mine yesterday. Or u may have a cracked intercooler

 

Well my g/f was with me and when it happened she didn't even feel anything, I guess it felt it because I was driving the car. Whenever I first got my charge pipes I didn't get them on good enough the first time and I had one blow loose from the coupler so I know what that feels like and this didn't feel or sound anything like that. It was just a slight jerk and boost just dropped, I guess you could say that I felt it in the pedals.

 

This is what happened to my car this past winter and I have seen several others had the outside wastegate nut come off my car was an early 08 and had no loctite on it. There is a tsb at the dealer for it with a locking tab on the nut. I double nutted the outside nut myself so there is no way for it to come off now
If it did come off just jack the car up use stands and look up just past where the dp connects to the manifold on the turbo not a fun area to get you're fingers either. Also if you fix on your own use stainless nuts because of the high heat and make sure you put back where they were before. You can see heat marks where they originally were or you will have more or less boost and could go into limp mode for over or underboost.

 

Ok so I have the car upon some ramps and I am checking everything out. I took the charge pipes loose, reseated and re-tightened the coupler clamps and I do not directly see any cracks or anything wrong with the intercooler.

The wastegate is directly below the turbo correct? I see a rod coming from it and going up into some kind of clamp looking thing kind of in behind the downpipe/manifold and it is threaded on that end. I do not see anything out of the ordinary. Everything seems to be tight and I can't seem to find any loose or missing bolts.

 

Well then it could still be the rubber diaphragm on your BPV or a MAP sensor is on its way out. You don't have a CEL yet right?

 

Already checked the rubber in the BPV, it looks basically brand new and I checked the sensors in the intake and cold side charge pipe, they look good too. And no there is no CELs. Is there supposed to be a nut on the very end of the rod from the wastegate, the end that is threaded? Because the threaded end goes through the clamp thing.

 

This sounds like limp mode.

What were you boosting to?

 

Yes one nut is before the clamp and one past there are 2 and it is not on the very end about maybe 8 threads back from the end of the wastegate rod.

 

Well it still has the stock 15 psi tune on it and then of course the 25 psi peak Trifecta tune.

Another thing as well. Last night when all of this happened it sounded like the BPV was louder to me and when I took the BPV out a few mins ago the rubber was suctioned to the plate and did not have that "plunging" effect and I had to pull it loose. And after I put it back in, it sounds normal now. Could the BPV have just been stuck? I haven't tried driving the car yet to see if anything I have done has fixed it because I am trying to keep from heating the motor up until I have checked everything out.

 

Well I do not see any nuts on the wastegate rod at all. It looks something like this.

---[ ]------------{wastegate}

 

Well, you can't hug every cat.

 

[QUOTE=DarkShadow;5903192]Well I do not see any nuts on the wastegate rod at all. It looks something like this.

---[ ]------------{wastegate}[/QUOTE
In this this post is a pic of the wastegate with what it looks like if the end nut is off they can and will just barely hang on by the threads sometimes though before they fall all the way off.


https://www.cobaltss.net/forums/2-0l...82/index2.html

 

Did you also check the cold side hose where it goes into the intake manifold a lot of guys miss that one kinda hard to see but usually when that blows off under boost sounds like a m80 went off.

 

Well I got it fixed, took the car and did a couple of hard accelerations and we are back up to 15/25 psi.

My issue was in fact that the BPV was stuck open, this is why it sounded louder last night when the issue occured. It was actually suctioned to the plate.

My wastegate acuator rod does in fact have both nuts, I just couldn't see them at first because they have a retaining clip around them. Thanks for the picture, it did help me to verify that I did in fact have both nuts.

 

Cool glad you got it fixed!! I may look into the forge myself lol not have to worry about that diaphram failing or collapsing.

 

Very true my friend and I was just considering that too.

 

Same thing happened to me this morning. My car was doing this before, but it was oil on the MAP sensor. It did it again, and it was a cracked turbo housing that time... I've got zero luck with this thing.

 

Shoot. I think I may have the wastegate actuator problem pop up this morning. I've suddenly hit the 5psi boost limit, and I'm getting compressor surge when I let off, even if it's in vacuum.

 

The wastegate problem I had seem to be a code for overboosting. What your having could be due to anything really.

 

If you put the pedal to the floor does the motor sound like **** and the boost gauge fluctuate a bit but never above 5PSI? Scan for a P0236, it won't set a CEL, and since it just popped up I'd doubt it's a random boost leak. This "5PSI" issue can be just about anything and I think I've seen most of 'em now.

 

I haven't had a chance to scan it because I noticed it this morning on the way to work. My LTFT and STFT aren't wildly off, so I'm not expecting a boost leak at the moment, but a scan for 0299 or 0236 will tell more.