Hello Everyone,


My name is Jason. I recently purchased a 08 cobalt ss in pretty rough shape but I didn't pay much and it only has 84k miles, so I picked it up for a project. There are countless problems and I don't know much about the car so ill be looking to you guys for help and guidance. There's about 3000 worth of body damage but that'll be saved for last. For now, lets begin with the issues to get it on the road.


The sunroof had been busted out, so obviously there was water damage on the interior. I have replaced the sun roof but during a rainstorm today I noticed water running in from passenger side under dash, as well as down the plastics in the rear just under the small windows. I assume that the sunroof has drains to wheel wells and these drains are clogged from previous sunroof being busted? Any thoughts?


It would crank at first and then run shortly and die. During the run it was black smoke from the tail pipe and I had to peddle it to keep it running. Im by no means an expert but I figured it was running rich? I unplugged the MAF sensor and it would run and idle fine. I replaced the MAF sensor, but nothing changed. Any thoughts?


Now the original battery is shot so I bought a new one and replaced but now the security light is on in the dash? This wont allow me to crank, everything electrical comes on but nothing with the turn of the switch.


I attempted to run codes but nothing shows up, even though engine light is on. I think the guy had it sitting for a while. Digital read out shows service - airbag, traction control, power steering, svc. previous owner said he had computer tuned and plug and play MAP sensors from zzperformance, but the lower MAP sensor seems loose.


When I drove it home, it would not build boost, it would go To zero and stay.


GOALS are to get it running right and then start upgrading parts that allow it to handle more power so I can build on top of that.


Ill have around 3 grand to put into it this month to get started on the build.


All input is appreciated..... ANNNNDDD GO!!

 

There are drains as you mentioned. You could use an air compressor and try to blow them through. Thats the only thing I've seen mentioned on clearing the drains. I hear the drains are notorious for clogging.


This is hard to diagnose as you have no idea what the codes are and if the car was tuned, was it tuned back to stock before selling? There is a whole slew of things that could be the issue. Clearly its running rich. Id start by posting photos of the car. any upgrades on the car, ask if things are oem or aftermarket. check to see if the MAP sensors have a blue sticker or are they black, etc. It could be as simple as there being an intake on the car and the cars tune is stock. These cars are sensitive to changes around the MAF.

Another possibility could be a boost leak is causing you to run rich. Like litterally your problem could be anything without knowing what the codes are for the CEL.

Ive heard of dying battery or a poor ground can cause this. Make sure you secured the battery and the clamps are secure to the battery. Also check the ground in the trunk where it attaches to the car.

This is simply because of your CEL on your dash. If the car has a CEL on, it goes into "safe mode" or "limp mode" which is basically no boost builds/ stays out of boost. Find out what the CEL code is for. If your not seeing any CELs, try disconnecting the battery for 5 mins and reconnecting to see if the CEL comes back.

Post some photos please and good luck! These cars are a lot of fun once you have it running right.

 

Okay, thanks. You told me more than I knew, lol. I will check the things you mentioned with the battery today. And he said he did the stage one tune and it was tuned for the MAP sensor upgrade. All zzperformance. Also if it was dead for too long would the CEL contain no history? It sat dead for months while i was putting the money together. so all parts are stock except for the MAP sensors and the computer tune for stage 1. Heres the pics for you guys.

 

I checked the Battery cables, inspected the ground connection in the trunk and tightened everything down good. Still no luck on cranking, security light remains on. I have read about a relearn process, I will attempt that while I blow out the sunroof drains when im finished typing lol. if I get it all cleaned up well and it still wont crank; I may have to take it to a dealer???

 

Gotta figure out what codes it has.

 

looks completely stock from these photos. Stage 1 MAP sensors for sure so it should be Stage 1 tuned.

I have an idea why the security light might be on. Its possible that he ordered a tuned PCM from ZZPerformance and threw it on the car but did not provide the correct VIN. I know when I tried to use a spare PCM on my car the first time, it did the security lock out thing. You can do the relearn process and that should take care of that. Also Id check with ZZPerformance and see if they did indeed put a stage 1 clone tune on the car or if its there own tune and they did account for stage 1 MAP sensors.

 

You really bit off a big project.....
This is something for a very experienced technician as you will go broke having a dealer work on this.

It is going to be hard for very talented members to devote a lot of time to this but I will throw some items to check in this order.

Make sure everything is plugged in.
Check all fuses, under the BEC lid (Buss Electrical Center under the hood) and in the interior.
Disconnect the battery ground for a couple minutes then reconnect.

You have an ESC error which is usually a defective TPS (throttle position sensor) in the throttle actuator (throttle body) Make sure it is plugged in all the way. That will put it in limp mode.

 

I thought ESC had to do with the wheel hubs, and speed sensors. Hence why his traction control is off.

 

My bad, I misread the acronym...

 

yep lol.

 

Cuda I spoke with the previous owner and he said that he had the stock pcm sent to zzp to be tuned and also the stage 1 MAP sensors were accounted for on that note. Atleast he said that he selected that on the options when he ordered the tune up before sending it off. He ordered the MAP sensors along with the tune.


I tried the relearn process with no luck, no matter how long the key is in run position the light doesn't blink or go off.


To the rest of the replies.. thanks for all the input, yes this is a big project, but I said I do not know much about this car, not cars at all lol. Im not a complete idiot, ive just mostly worked on old classics, so yes this is a little out of my experience level.


Im not gonna have a dealer do all work. I have a mechanic that will do me justice on labor for things that I don't think I can handle.


The car sat for almost a year completely dead, so I guess this is why it shows no codes? it hasn't ran in so long? it needs to run I order for the computer to learn everything that is wrong?


If I can get it cranked or the dealer, ill bring it back and run the codes to give me more info.


I will check all fuses as well before I get it towed to my dealership here.

 

Also cuda, I blew out the drains on the sunroof, I poured water on it with the hose pipe for a while and checked inside. didn't see anything running in, I believe it may have worked, but we shall see.

 

Also guys im looking for some suggestions on best places for some parts.


I need fog lights, front bumper, gear shift assembly, and replacement front seats.


fog lights were knocked out and front bumper damaged by deer collision.


gear shift boot is worn out.


front seats aren't in terrible shape but the bars to slide the seats are shot.




Cuda, the previous owner believes there was a boost leak as well... Any places its notorious for springing the leak?


I'd assume in the down pipe or crack in the intercooler or something?
I can check the intercooler when I remove the front end to replace bumper.
might as well upgrade the piping and intercooler while I got it off...?

 

Check the intercooler for cracks. If its a stock intercooler with the plastic end tanks they are famous for cracking.

 

GM Parts Direct: Your direct source for Genuine GM Parts, Crate Engine Depot - Chevrolet Performance Parts and Engines, 2008 CHEVROLET COBALT 2.0L L4 Turbocharged Parts | RockAuto,

Id check rockauto.com or amazon. I think you can find decent foglights there. I dont know about checking a junkyard, theres not alot of cobalt SS's around to find some in decent shape.

http://www.rockauto.com/en/catalog/c...p+assembly,803
^rockauto has foglights. There bumpers are for base models though.. not sure where to find a cobalt SS bumper from.

They all turn to crap eventually even with the best care. There are some aftermarket boots available out there but I'd just find a factory one on amazon or something.


^This looks pretty good for replacement boots.


Theres a few spots to check. You could make a quick boost leak tester with a coupler, clamp, PCV pipping capped off with a barb to attach a compressor too.

You would take the charge pipe off after the turbo and connect the boost leak tester contraption turn on compressor for a sec and spray soapy water all over everything on the intake side to look for bubbles. Also you could connect a guage to see if there is boost drop after turning on the compressor, just dont over compress air into it lol.

But without doing the boost leak tester you can check the following:

#1.) Intercooler. Factory intercooler has plastic end tanks, they are notorious for cracking under pressure especially after multiple winters and summers which is all the cars at this point.. Another location to check on the intercooler is if the condensation bar is damaged underneathe the intercooler. If that is broken off due to a curb or something, it will cause a boost leak.

#2.) The factory charge piping is plastic, Ive seen them crack and break just not as often as the intercooler endtanks.

#3.) The MAP sensors, I understand he had the Stage 1 MAPs installed, hopefully the correct rubber o-ring was used. There was a point when this kit came out that people were using the old o-rings with the new MAP sensors and they did not create a nice seal. The lower map is screwed into plastic so you would have to be super careful not to strip the threads if you take it off to check. I feel this is least likely the issue but you can check with the boost leak tester by spraying the soapy water down there. <-- best way to check.

#4.) I've seen the brake booster hose which connects on the lower right of the engine cause a boost leak. Very minor but the owner sprayed soapy water with a boost leak tester and saw bubbles there.

#5.) The factory BPV diaphragm. It is rubber and can degrade over time. I have seen a few tear from stress and use. To check that, remove the BPV from the stock turbo just by the intake. A vac line is attached to it and it was a tan color to the cover held on by three screws forget the size. 10mm?

#6.) Other areas to check since the car hit a deer.. Possibly a boost line or vac line disconnected and has not been reconnected. Check all vac and boost lines leading from the turbo and connecting anywhere on the intake side of the car.


#7.) Last idea about the boost leak, maybe one of the couplers has a tear from overtightening it. That is a possibility as well.

I do not believe you would see a boost leak from the down pipe. The downpipe does not see any boosted atmospheric air, just exhaust.

 

Cuda, YOU ARE THE MAN! Thanks for taking time out of your day to offer so much insight! I saw you tube videos about the tester you mentioned making... pretty simple!


I think Im gonna go ahead and replace the stock piping and intercooler when I take the front end down, I get my bonus the end of the month.. ill order parts and see if the dealer can replace that recalled ignition and get it to crank. that's as far as I want them to go but im sure they'll try to hit me with some bs lol. If I can get this thing running like new for less than 5 or 6 g's ill be happy.. Hell it only has 84k miles.


Are there any brands when I go to looking for parts that I should steer clear of? like ppl have had problems with... I see zzp is pretty common, so I assume they are reliable.

 

Thanks for the tip! will do!

 

Have you gotten far enough to see if the turbo is siezed?

 

Not yet buddy, the previous owner said that it wasn't, that he could hear it trying to spool it just wouldn't get more than 1 or 2 pounds of boost... hence the boost leak theory. Let's pray that its not for my pockets sake lol but if so we'll just be making this an expensive build or ill sell, that's the options lol hope not tho. he seemed honest and hasn't avoided contact since the sell.

 

Yeah, when you said Zero earlier that's a bit more than a leak, hence the seized question.
If you were in Denver I would have you completely diagnosed and running in no time. I can scan an engine and figure it out faster than I could type anything. I did the GM Western Region diagnosis prior to a buy back. I was the field engineer that got the 3rd try and in my tenure we had zero buy backs due to drivability.

 

How about a blow off valve stuck open? I would assume that would allow for no boost to build... but I read somewhere they has a bypass recirc valve for the no lift shift feature... does this operate completely different than a normal bov?

 

also wastegate maybe messed up but I doubt it.

 

So I put the car on jack stands yesterday, removed the front bumper and began to inspect the engine. I got up under to inspect the end tanks and condenser ... and check out the pics lol... I'd say I found the problem!


Any recommendation on new intercooler and piping? im gonna replace all that as well as the front bumper before I have it towed to the dealer to get the security issue and ignition replaced.


thanks for all the guidance!

 

If your turbo ends up being shot, I have the stock k04 I took off mine to put my ZFR on. It has 90K on it. Id let it go cheap to help you out.

 

Thanks! Good to Know! I should know in less than a month.