Baron7700

Ok all, so this has happens to me 4 times (twice all day) over the last two weeks and its just really weird.

I have gms1, and a hahn cai. its been great for almost the year Ive had it on with no problems, and really no skew issues.

THhe last few days its been 100+ here in Pa, and I think this has to do with it when you hear my problem.

First off, I did a lot of forum searching, and the common problems seem to be, boost leak, vac tank, stuck valve, maf, fuel trims, etc. well this is what happens.

At first I thought it happened when it was really hot out, the car wont boost past 5 psi, is incredibly slow, and getting **** for gas mileage (even when it seems to be boosting fine). I thought it was since it was so hot out, and with the intake, the fuel trim got really fucked up, and eventually threw a CEL. For the most part, after a few starts of running around, or some time off the car goes back to normal, but sometimes stays messed up over night.

Also, when I cant boost, it spools up and instead of a clean bov sound, it flutters, like someone is flopping there cheeks, doesnt sound to goood. I did throw one CEL, but I have to find someone to pull the code for me, i dun want to rip the intake off and put stock on one just to bring it into dealership for them not to be able to repeat it.

What are some of the things I should check first, This is my first turbo car, So i dont have a good idea, how or where to check for a boost leak. Also, could someone post a pic of the engine bay, I think one of my vac lines is missing a cap or something which could play an issue, but nothing is glaringly broken.

Whenever the car is cooler it seems alright, although when I did throw the code it stayed for almost 2 days, and finally went off overnight when I had barely driven it the day before, so I was just assuming it was the insane temps throwing my MAF off with the hahn and what not, but it still doesnt feel 100% when boosting, and again my gas mileage is down without me changin my drivin habits, so Im just curious as some things to check for and where to look to make sure everything is tip top.

Thanks guys.

Iam Broke

iTrader: (10)

Since you are running the GMS1 tune and a Hahn intake, I can tell you your fuel trims are off by 12-14% without even logging it. Since you want to keep your warranty with the GMS1, take the Hahn off and see if your problem goes away. I'm betting it will. You can always mod the stock airbox if you want more flow.

If the problem doesn't disappear with the stock airbox, you're all set for a dealer visit anyway.

turboss09

my car has been in and out for this problem about 5 times, they replaced the map sensor, the new one that comes in the kit 3 times on my car and guess what that wasn't the problem. The did a vacuum test and said it was ok. They are having a district engineer come out and try and figure out whats going on with the car. Oh by the way from my personal experience when the car acts up it does it little by little and then gets worse the more you drive it, the computer gets so wacked out. It cut out so bad one day that i turned around and drove right back to my house and had it towed to the dealer.

importkiller

iTrader: (1)

I am having the same problem. I was hpt tuned with aem intake, charge pipes, and down pipe. Even with all that off stock stuff on and my stock ecu it is still doing this. I has been in the dealership for almost 4 weeks. Each time it is in and they say it is done it still does the same thing. They have replaced one map, one maf and now they are going to replace one of the o2 sensors. I am thinking its a boost leak on the intercooler but they wont listen to me.

peachpuff

So many of these problems can be easily fixed if you'd know what the ecm is doing, if you don't have hptuners its simply a guessing game. Hptuners should be a necessity if you're modding.
importkiller you probably have the same issues as the op, your fuel trim is off the charts(possibly due to the intake or a boost leak) and the ecm is shutting you down, but until you do some logging you won't know this.

importkiller

iTrader: (1)

Yeah but the problem is I went back to 100% stock including stock ecu with stock tune and it still is messed up.

ctn2mb

iTrader: (2)

im actually willing to bet your running your ac when it happens... since the map sensor on the lower charge piping is right by the sensor it causes that

SSlobalt

Sounds like a boost leak.

turboss09

Ac has no effect on my car i hardly ever use it and the car acts, but i have heard of ppl having the issue your talking about

ctn2mb

iTrader: (2)

well i understand ac doesnt affect the car im stating when ac leaks like its made to do... cause its so cold it leaks onto the sensor.. thats what my friends problem was...

peachpuff

Even stock intake and intercooler pipes? There could still be a boost leak, don't rule it out.

Baron7700

It goes back to being alright after a bit or when it cools down, I know my trims are off from the intake, and just figured it flipped out when it was 105 and already skewed, and it didnt know what to do with itself, when it boosts fine, the car runs normal, just weird.

If i disconnect my battery, and reconnect a few mins later will that wipe out the learned trims and go back to stock, than just have it relearn the intake. I.e. will it relearn its fucked up but not as bad as it has been?

Again i really just like the sound of the intake, but and it hasnt been much of an issue so far, but if this continues I might just get rid of it and throw a DP on or something.

SSlobalt

Well, that sounds like the IAT2 sensor going bad, then. Someone else had a problem similar to this.

Terminator2

You could have Ryan (PrincessTurbo) scan the car and send me a log of it. I am pretty good at diagnosing issues even from 1,000 miles away.

Baron7700

well this is what happened today, Go out at about 7:15AM and its still pretty cool out, get back around 1030, and put in the garage. @ about 12 I go on my lunch break, after about 15 mins of sittin in the sun I go to run some errands before i go back to the office and the car is fine. After another 30 mins of sitting and on my way back to the Office, I go to pull out of my parking spot, and I can instantly feel that the car is bogged down in reverse/first, meaning i prob cant boost either. So i rev to 3k in first (not flooring it or anything just lettin it spin up) and shift to 2nd and the the great stutter is there, awesome. Of course it wont boost past 5, and the car is slow as *****. Im really just thinking it when it heats up it gets all kind of skewed, is this normal for an intake on GM tune, or do you still think i got a bad sensor or something.

I think im going to put the stock intake back on first chance I get and see what happens after a few days, maybe there will be a Hahn CAI on the market soon.........

lifeguard15

My car started doing this a month or so ago. Most of the time it won't boost past 5lbs, sometimes it gets stuck at 15ish. It's random, sometimes it will give me full boost after running for a while even if it started in 5lbs mode. CEL is on and off, I just haven't had the time to take it in to the dealer.

Baron7700

ugh, and your all GM? maybe its not my skews than, that would suck if i have a bad sensor or something. Either way, If I bring it into the dealer, you know I gotta take the intake off for anything directly involving the turbo....

lifeguard15

Correct, I even have stock filter. It's very annoying. I might take it in on Wednesday.

Baron7700

ok so the car now hasnt thrown a CEL in like 2 days, and it boosts okay, but my gas mileage is down about 5mpg in all apsects without any change in driving habits, with the noticeable decrease in mileage I actually drive more efficiently and still getting horrible gas mileage, i think I average about 19.8 right now, getting like 240 miles to a tank, and I have only driven it in such a way were gas mileage should go up! I was normally getting 25-26mpg average on a tank.............I would think by now the car would go back to what it normally was with the intake, I guess a sensor is fucked up? I am taking the intake off this weekend.

Baron7700

ok my new issue is that the car "boosts" fine, as in it seems to spool up, but the boost never seems to really hit the motor, i.e. the car is still limping around somewhat. Its driveable, but is no where near the power it has.

Second Issue, on the RPD, it occasionally says "No Data Available" on the boost screen, any ideas? Maybe I have a bad sensor??

Mcksxy2008

I bought my cobalt uesed and it was doing the same thing it took the dealer about a month and a half to fix it. It ended up being a couple boost leaks in the charge pipeing and a couple faulty clamps.

Baron7700

ya i think thats what it is too, i was at a weekly car meet and it started doing it last night. So we popped the hood and revved it as we tried to find where the nose comes from, sounds like its where the intercooler and cold side piping are.....

funny thing is I think the comp learned the leak out, because now it boosts fine, but it seem like it never reaches the motor....

dys

I have been experiancing these lack of boost issues people are talking about ( charge piping and connections are fine). I have a 2008 SS Cobalt with the gm stage kit. Drive it and it perfect , spiking 26 psi and leveling out to 21. Park it for a few and then it will only boost to 5 psi (completely random). After reading a few articals on the stuck wastegates I tried a simple thing. Using the wooden handle of a hammer I taped a few times on the turbo housing to see if in fact I could unstick it. Works every time, Car is going into the dealer in a few weeks to get it fixed right . For right now I have the hammer handle behind the seat. I have not hooked it up and checked codes, it doesnt throw any visible ones on the dash when it happens. 5 psi really sux when your used to 21+.

whitey_rolls

For those with the Stage 1 from GM who are having random drops in PSI there is another thread that might have found the problem.

In the GMS1 Kit they provide Butt connectors for all the wiring. It's believed these don't hold the connections very well and have been causing a lot of problems. Check the new sensors that were installed and see if they used butt connectors. If they did ask them to solder the joints instead.

Numerous people have had similar issues that were resolved by soldering the joints.

Sn0wblade

I've been having the same problems lately... all stock GMS1...

It is going to the dealer in a week.