ok well I said I would update you.. so here it is..

Per recommendations, I performed the Boost leak test. it resulted in one "micro" leak on the hot side charge pipes down to the IC. so I fixed it. took the car out for a test run.. still noticed the stutter, but at a reduced rate. However the problem still existed to some degree.

I decided that maybe because of the airbox leak I had with the new ZZP piping that I installed in there, that maybe the MAF got contaminated in some way with particualte matter or something. So I cleaned the MAF ( properly ) . I also re-adjusted the hose length on the clean air inlet that ZZP provides with the hose for the intake, ( its a low grade mallable aluminum ). I made sure it was as in the middle of the pipe as it could be.. cut it down to the right size, polished the end...locked it into place.

I used some composite aerospace grade high temperature bonding tape ( amazing stuff btw ) to also cover the hose ends on both sides of the intercooler, since that was the new install and figured if there's a problem, its gotta be surrounding that, so.... even though the clamps should be enough themsevles.. I thought, can it really hurt? I dont think so.

since the MAF clean, and the leak adjustment, tape job... I've ran the car for about 4 days now. The result has been a much more subdued ride.. the boost spiking has ceased.. however there does seem to be some "very slight" surging here and there, but I attribute that to my pedal response and ECU adjustments on the fly..

there is still the outstanding issue of the wiring with regard to the upgraded Baro sensors from the GMS1 upgrade. specifically the lower one on the IC piping under the car.. I still think there might be something going on there.. but im not going to worry about it unless the cars performance goes wacky.. then again, I wouldnt even know what would happen if it went bad or if anyone else has had that issue.

for now though, I am ( with baded breath ) , happy with the cars performance.

 

Good news! Glad to hear you have figured out the issues.

I'll have to get the parts together to do my own boost leak test during winter (car is stored now) and see if I can find anything. I'm also going to check the EVAP solenoid which seems to go bad and see if that's working properly. I'll update you if I find anything, however it will be until next spring/summer before I will be able to drive it and see if the issues are fixed.

 

sounds good.. let me know what happens.. the EVAP solenoid is a good one to check..but the boost leak is always a good place to start.... especially when upgrading.. adding parts.. or removing them... it almost seems like it should be a default step to check / re-check your work before turning the keys.. that way you omit it from the discussion.

 

Well..... Im stumped.... todays start up and drive off was filled with weird noises and stutters all over again... I spooled up to only modest pressure.. 6-10lbs.. and got what sounded like a drivebelt that needed replacing.. except it felt like it was coming from the turbo. I don't know WTF is up.... after a bit of driving.. and a couple start and stops... due to my errands I was running.. it evened out a bit... but when I went to press the gas just a bit.. it surged hard then dropped off boost pressure.. RPM's stayed up... its like its out of sync or something..

I just don't what could be causing this issue..

 

ok so my frustrations turned to anger... Could I be missing something... another boost leak??? I had to try again... so I went down.. stuck it on there... almost gave up until I was under the car.. feeling **** out with my hands and low and behold...

right where the GMS1 upgraded sensor attached TO the IC pipe on the lower side ( basically at the bottom of the car ) ... a leak... HOW in the F$#^ am I supposed to repair that? its coming out of the fitting that the sensor fits into?!!

I tightened and loosened the screw holding it in... I got some reduction to the leak.. but the sensor felt loose.. makes wonder if it was installed properly or the direction of the sensor is off.. right now its 90degrees to the right of the IC pipe.. facing towards the back of the car...

and a quick search on the interwebs suggested that its position is right.. so Im not quite sure how to get this fixed.. epoxy? maybe it just needs to be seated better...

 

What color seal is on the sensor?

 

Sounds like you have the wrong o-ring on it. Remove the sensor. If it has a greenish blue oring on it, you need to remove that and put the right one on there. Crate engine depot has them or Wangspeed can tell you the oring size.

 

Wrong o-ring as mentioned above or time to upgrade the lower charge piping. Mine got stripped so I got the ZZP unit.

I've been having a similar issue now and then. Check your vac/boost levels when it does it. Usually it should be -22 vac or so letting off the throttle. Mine does it when its anything less than -20. Hints at a boss leak but it does it every few weeks so I think electrical.

 

thanks for the replies:

the color of the O-Ring is Green... that was the color frm the get go out of the packaging that came with the GMS1 upgrade so far as I could tell.. I found the part on Crate Engine Depot.. so its on the way...

as for the ZZP Piping ... was the fitment for the sensor better than stock?

 

Much, the GMS1 sensor is moved vertical. Hard to explain but its basically on the upper end near the throttle body now.

I was sick of my issues so I finally upgraded, plus my OEM one stripped where the screw went in due to cheap plastic.

Not going to read the entire thread again but I think the thread below mentioned similar problems. I haven't looked into mine yet as I've been busy.

https://www.cobaltss.net/forums/08-1...ircuit-190417/

 

https://www.cobaltss.net/forums/part...e-pipe-313009/

 

For now, i'm gonna just shoot for the O-ring, if that doesn't cut it... I'll get the pipes... don't feel like spending the money if I don't have to if this is gonna take care of it. Thanks for the link to the pipe though.

so far since the adjustment to the sensor, things have been better.. but its not 100% .. so I should be getting the O-rings by mon-tues this week ...

will post update once installed and driving around some more ..

thanks again for the replies you guys.

 

Tightening the sensor or does so much, the sealing is from the oring and when you get the 3 bar maps you have to order new orings.

 

ok so.. another update.. I got the O-rings in.. removed the original green one.. hell even in the GMS1 installation guide pdf it even tells you to replace them, which the dealer never did. well in the process of doing that, I dropped the damn screw that holds the sensor on the pipe into someplace on the car.. I cant find the damn thing.. tried a magnet .. everything.. so my frustration turned to action and so I went to the hardware store and purchased several screws that resembled my memory of what it looked like... well I got lucky!! I chose 6 different ones and the first one I guessed would work did!... I even decided to upgrade to a better type of screw and added in a washer.. sealed the screw as well so absolutely no air could come out...

so now you're giong to Love this.. I get everything back together.. take it for a drive.. feels sooo much better.. stable... AFR's not bouncing around as much.. the Surge is gone... so I decide to giv her a few "fun runs" and the first one I did.. BAM blinking check engine light!! WTF!!.. well it dissapeared after just a moment.. and never came back .. so I assume that I might have over sped the RPM's but I really dont think I did.. so.. ok.. a day passes..

today im coming into work.. its driving nice... I decide to give her another "fun run" from 3rd to 5th.. careful to watch the RPM's .. everything is fine until I stop at a light and then suddently I hear what sounds like stuttering almost even misfiring in the engine.. rattles like I bent a Valve or a lifter... " but No check engine light came on", but it felt rough for about a minute or two .. OMG did that screw that I could never find, some how get sucked into some part of the engine?? .. nahhh couldnt be.. it fell downwards possibly into the bottom of the twin cooling fan housing... but never the less.. I got stuttering for like 3 minutes.. then it went away.. ran smooth... idoled fine.. no weirdness at all even when I parked it and let it Idol..... so Im wondering when I stomp on it, whats happening .. I'm gonna be looking harder at the MFD for AFR's and knock sensors. but I also dont want to push the car..

anything else want to go wrong with this car??? ... any ideas? I havent done anything to this car other than fix the boost leak, and replace the screw.

FML

 

Flashing check engine light is misfires. How old are you plugs? and what are they gapped to?

 

^This. Pull the plugs and check them out. You can try seafoaming too.

 

Also if someone near you has HPTuners, make a log of this, record injectors, misfires, lambda, MAF freq, throttle blade position, knock, map. You need help PM me I can set up a config file and email it to you.

 

Hey teacher I'm raising my hand. Pick me.

How many miles are on your car?

Check your plugs first and replace if over 50k.

Lastly, check your intake valves for build up. Will need to get a camera borescope or pull the intake manifold and check it out.

 

Major, on your fun-run, did you hit the rev limit?

If so, do you have a raised rev limit, like 7k RPMs?

 

hey guys.. thanks for all of the replies..

I ran a code check and it came up with the 0308 Cylinder misfire like you said...

I thought I "might" have over revved it.. I told myself it was possible since I wasn't keeping a solid eye on the RPMS 2 days ago..

however , yesterday, I was SURE I didn't do that.. and it happened... coming out of first into second was kinda scary since I thought it was gonna leave me on the side of the road..

in so far as the plugs.. They are original .. car has 66K on it... so I can order some NGK's or whatever is the best for the car...

I seafoam usually once a quarter...

The carbon build up.. I honestly don't really want to open the engine up on my own.. I've had a lot of experience watching people do this.. and once its cracked. it seems like its never the same after its been put back together.. in all honesty I probably don't feel comfy enough with doing that on my own .

as for the HP tune.. I had it tuned about 3 years ago... I haven't done anything else to it.. it was tuned from a friend of mine at my work.. he left.. so I have no access to a tuner or being able to log anything on my own.. so Ive become an Avid RPD watcher for AFR's .. and knock sensors overlap etc... obviously I can only see one thing at a time.. AFR's bounce around... with throttle input.. shifting etc.. but under a progressive throttle.. they even out to right at 14.5 to 14.9 so I feel like things in that area aren't too bad??? but I agree if I COULD log.. I would..

I think the thing to do.. is get plugs.. the car in normal drive feels fine.. I'm going to stop any fun runs immediately.. Im not about to damage it anymore then I might have already.

after that?? what do you guys suggest

 

SSlobalt.. I thought the GMS1 / HP tune raised the limit some?.. but I tend to TRY to stay below 6K .. just because I feel like the power band really flattens out here anyway so I am usually pretty cog nascent over that.

 

whats the best Spark plug for the money for THIS car.. I know NGK is always respected.. and in so far as gapping .. Im not sure what the standard gap is.. I know HOW to gap.. but I haven't done a change to this car yet.

 

Stock ACDelco gapped 32

 

Im certainly not against sticking to stock... if that's what's good enough.. I'll roll with that.

 

you know I was just thinking about it.. when asked about seafoaming.. I tend to put mine in the gas tank..

I hear there is a method of letting the car sip it into the intake manifold through the vacumn tube on top of it.. then turning the car off... letting it sit for 15min.. then turning it back on... burning out all of the junk for 10 to 15min of spirited driving then, oil change and spark plug change right after...

if this is the process that was being talked about earlier.. please let me know.. I'll do this tomorrow..