and so it begins....

 

I'm sure GM will have a software update

don't get your panties in a bunch

 

I'm so relieved now! Thanks man!

 

LOL I know, i was just waiting for the problems to start w/ the TC's...

 

You might be getting some knock retard with only 91 octane (depending on your driving conditions). You don't have access to 93 or 94?

 

No I don't. California is stuck at 91 as far as I know.

 

http://www.chevrolet.com/cobalt/specifications/

I said before 91 is fine & chevy even says you don't need 91, but I would put super.

 

I have the exact same kind of leak issue, but it doesn't happen all the time. It seems to happen only when I follor it at 2500 to 4000 rpm. But from a start, each gear is pulling hard, no hesiation....

 

Weirdness I just got this happening on my car too. Any updates? I'm taking mine to the dealer.

 

ok no need to start busting on the turbo cobalts just bc there are some problems. Im just saying, turbos require more things to work properly that s/c do. But since its from the factory it should be fine. Bring it to the dealership and they will fix it or get you a new car. just dont mod it

 

My car is with the dealer now. Took the mechanic for a test drive with me and reproduced the problem. He didnt seem as convinced as I was but that's just because he never drove the car before this issue started. I know I'm not crazy, lol, there has to be a problem. I'm gonna guess it's a leak of some sort. Hopefully it is a very simple to solve issue. I will post again when I hear from them tomorrow.

 

I never took mine into the dealer after starting this thread. I am at 850 miles right now and the problem is gone . Let me know what you hear. It seemed to slowly go away. The car is running VERY well now. Maybe I had some bad gas or something? I have had very bad experiences with the gas stations around my area. In my Acura RSX I used to get spark knock if the gas was not good. It happened very often. Anyway, good luck!

 

Glad everything all good I want all the bugs out of this car for 09 in april
Well good luck

 

I am hoping it was just a hiccup but it happened consistently all day today....so I dunno. 874 kms on the odometer.

 

drive it like you stole it and see what happens

 

Already attempted that yesterday. No abusing, just full throttle from about 2500rpm. Issue continued to occur.

 

what the hell does follor mean??

 

I just re-read this and am thinking...you say the boost spikes to 17psi or so. I think what is happening is the PCM is pulling timing and/or throttle because it's exceeding the ~15psi threshold that it's trying to maintain. I notice my car tends to 'fall on it's face' right after a boost spike. Until we get some more detail from the guys digging into the PCM and the electronic hardware that controls our boost levels, this is just a theory. But going forward, try to see what happens with boost when you experience this issue.

My other theory would be burst knock retard. I know the LS1s have a few tables that pull timing on rapid throttle changes. They might have something similar burried in the PCMs for these cars.

 

He misspelled floor. Read the full sentence and it's pretty easy to make sense of what he tried to write.

 

follor
floor


Who was typing, Michael J Fox?

 

ROFL! Just heard form the dealer that the car is ready. They have sent the scanned info to GM to analyze. In the mean time they have reflashed the computer and the problem was not occurring. I hope it doesn't come back. Will keep you guys posted.

 

They may lying to you. Make sure they are really sending the data to the performance division. Also, I have a theory of what may be causing this problem. Read my reply below...



My car also seems to fall on it's face after a boost spike. When I accelerate from a stop, the car never has a boost issue, the problem only occurs when I am accelerating from approximately 2000 rpm. I do have a theory for this crazy problem that is not quite as technical as yours, but may offer some hope for the problem.

I was sitting at a red light last night and I looked to my left at a Honda Civic. The guy was laughing at me (I'm assuming he was doing this because my car sucks compared to his amazing Civic, lol) so I eased into first gear and quickly accelerated through the gear. As I did this, the gas pedal was all the way to the floor at approximately 1,500rpm. The car ran great all the way through the gear but at about 3,500rpm, the wheels broke loose and my car jumped to redline. I was VERY surprised! I did not use launch control and I was not in competitive mode. The traction control was on. Getting to my point, I think that the traction control, although it did not work for me last night, may be causing the car to hold itself back during acceleration. Maybe it is attempting to keep the tires from breaking loose but to us it seems like the boost is being cut and the car is not performing well. This may be a long shot, but it is an idea....

A side note: The road I was on was not wet and did not appear to have paint or any oil on it. I'm not sure why the wheels broke loose so badly.

Jake

 

I know why your wheels broke loose...260hp did it...damn bastard!

Traction control does cut power...this isn't anything new...

I think the other issue is that we are seeing people on internet forums getting all riled up over nothing. Now you have everyone claiming their car doesn't make any power and blah blah blah...

Group mentalities suck...

 

The data wouldn't do **** at the performance division, they need to send it to the ecotec service engineer who will send it directly to Bosch who did all the calibration on the LNF.

 

Sweet, that is what I should have said . Thanks man...

Jake