If you've read my intro thread you'll know this is my wifes car. I dont drive it very often but we went to vegas in it this weekend from So Cal. and I drove it all weekend. Its a 2010 ss with 1,500 miles on it. It boost 5psi in first and around 15 psi after that. Well sometimes it would only boost 2 psi in first and 5 after that. Conditions were the same. At one light it would work fine the next it wouldnt. I'm not racing it just a little aggresive driving. some times on the freeway as well. I would go to pass and it would work and the next time no go. Im worried It wont be there when I really need it or if I wanted to race it would be really embarsing if it didnt work.

Thanks for any advice and sorry if this has been discussed, I looked around and could find my exact concern.

 

That's definitely not right. No check engine light? I'd take it to the dealer. It should be boosting 14-18 psi depending on elevation, atmospheric conditions, etc.

It also may be in reduced power mode. I think if you turn the car on and off 3 times it will reset. Most likely it threw a code for something though. It's also possible you have a boost leak. Check the intercooler and the charge piping for cracks.

 

Bad BPV?

 

Sounds like boost leak or misfire. Check the PCV line going into the air intake just to be sure it's not broken. If you have the ability to run a boost leak test, do it.

 

has it been doing this since vegas, could have just been the weather or something. get on it hard and see if it boosts up to 15, in first boost really doesnt matter, its not needed haha.

 

Do you have OnStar or a code reader? If there's no CEL you might have the P0236 (which doesn't seem to throw a CEL ever and I've had it twice) for Turbo System Performance. This can be anything from a boost leak to a failing TMAP/MAP. I'm not sure if there's a problem on the 2010 like the 2008/2009 where the lower radiator support bolt/screw is known to puncture the charge piping because it's too long, might want to look at that as well. I think my issue was on the hot side but the bolt/screw comes pretty damned close to the cold side as well.

 

Pic?

 

How about the whole TSB :


Service Information 2008 Chevrolet Cobalt | Cobalt, G5 (VIN A) Service Manual | Document ID: 2195686
--------------------------------------------------------------------------------

#PIP4485: Low Boost, Reduced Power and/or DTC - keywords air cac charge control cooler driveability ecm engine gas hole lnf low maf mil P0101 P0299 P2178 pipe power reduced reducdpwrmde rub ses start stall - (Sep 26, 2008)


Subject: Low Boost, Reduced Power and/or DTC


Models: 2008-2009 Chevrolet Cobalt SS Only




--------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
If a technician encounters a low boost/power condition and/or dtc, the following may help.

Recommendation/Instructions:
When a technician encounters a low boost/power condition and/or related dtc on a 2008-09 Cobalt SS they should inspect the right side CAC-(Charge Air Cooler) pipe for contacting a radiator support bolt. Due to the location of the CAC on 2008-09 Chevrolet Cobalts a radiator support bracket bolt on the right front may make contact with the lower charge air cooler/hose from below. This contact may cause the CAC to leak boost or vacuum if a hole is present. Review the illustration to see the location of the suspect bolt. A thick washer may be added to the bolt to increase clearance.

Note: Bulletin 07-06-04-029 should be used to diagnose the charge air system when leaks are suspected. This bulletin may be aided by using the evap smoke cart to introduce smoke to the CAC system.



1) Right lower radiator support bracket

(2) Right front lower Charge Air Duct concern

(3) This bolt will wear a hole in the Charge Air duct

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
Š 2009 General Motors Corporation. All rights reserved.

 

That should be a recall, they should just change the bolt to a shorter one. Simple fix. Anyone know the size of the said bolt? I want to go buy a shorter one.

 

My bolt has been totally removed. There's 3 on the support, one points up-left, other points up-right so that should be more than substantial suupport on it. Worst case put a 1/4" washer (or maybe a bit smaller) between it and the lower part of the bracket.

 

Good find Permafried. That may be the isuue some of us might have

 

That's how they completed the tsb on mine: they removed the bolt completely.

 

Where you at in So Cal dude... I have HP tuners and a datalog of your car will more than likely reveal the culprit. I confess I am not the end all be all of reading logs but with that posted, someone will be able to find the problem.

 

If I read the post correctly the OP says the car was boosing to 15 in all gears but first. IN first gear he was seeing low boost. Which tells me everything is working fine, first gear typically doesnt boost as high as all the other gears, and to more than 5 psi I find that you really have to get on it hard from a slow roll in first.

 

which part of socal you guys from??

 

OP I just read your original threads... do you still have the BOV on? If so is it tuned properly and is the MAF relocated? If your MAF is still in the intake, before the BOV in the air path you will be losing metered air and should be throwing codes, at least some kind of code... P0101 or P0100 for me. When I finally relocated my MAF and tuned for it the car ran fine. It sounds like you are having the same issue I did when my car would go into limp mode because of the MAF... the same boosting issues happened for me.

 

The BOV was the problem. I removed it and all is well. I think the valve was getting stuck open some times which is why it would not build boost sometimes. Lesson learned.
The Bov is now attached to my tool box where its causing less damage.

 

just get a k&N sri, and forge bpv and you will be happy.

 

Motox wins that one. Crappy ass BOV's are more trouble than they're worth.