2005 Cobalt 2.2 no start

[GD60]

Hey guys.

New to the forum. Question about my no start. Car ran fine over the last while. It sat for maybe 5 days. Go to start it and it acts like the battery is dead. like we left a light on or something. which we didn't. Battery is 6 months old. I go to jump it with a known good red top optima from our audi and when you turn the key over it sounds like machine gun fire. Like the start motor is trying to engage but its not catching. no matter where i ground the negative side of the jumper nothing catches and all i get is this machine gun fire sound of it trying to catch. I've tried using different keys. OEM and non OEM. I did notice that the instrument cluster will say reduce engine power and the check engine light is now on.

If my altenator was going wouldn't I still be able to start it and then watch the voltage die out/fade with a multimeter? I can't even get it started to test. No idea what to check. I've gone through the fuses on in the engine bay and the 2amp starter fuse in the cabin. all seem to be fine.

When I turn the key to on/ignition it will try and start the car and continue the machine gun sound until i turn the key off. At the end of the video I leave it for a while and it just struggles with itself. Really not sure what to do or what to check.

any ideas?

 

[GD60]

Ground straps seem to be fine. I took a wire brush to the starter terminals and other ground locations in the bay and issue still presists. You can hear the solenoid getting power as it continually attempts to come on. however there is no draw for the starter motor itself. Every time I start the car i'm trying to jump it as I know the battery doing the jump is great with a ton of cranking amps. what is the procedure to determine if the starter is bad itself?

 

[GD60]

SO i put 12v to it and it started for a half second and died. did this MULTIPLE times. the security key on the dash was lit up. So now i'm thinking its Ignition switch due to:
-the ignition switch regulates voltage to starter motor
-ignition switch also works with the security system as well.

Thinking its time to replace the switch.

Thoughts?

 

[YelloEye]

Did you try getting the codes read?

 

[Corey]

Hi I thouight I might relate a situation that happened with my daughter's Cobalt just this week. She arrived home and the car reported on the readout that it was "entering battery saver mode" or something similar. I did some searching and found out that this means that the voltage has dropped below 10.7 volts. This was strange because the battery is fairly new and she had no prior issues. She also reported a strange "whining" noise from under the hood. When she went out to start it a couple hours later, it was DEAD, DEAD, DEAD... As in deader than I've ever seen any car that has just been run a couple hours earlier. I put my heavy duty battery charge on it and it pegged the amp meter at 70 amps. This was truly a dead short situation. I've never seen anything like it. I disconnected the cables and charged the battery overnight and got back on it the next day to see if it would start, which it did. The whining noise under the hood was pretty easy to hear and the battery was being sucked dry again. I put a fresh battery in it from a different vehicle and again, dead short, heavy draw from the battery terminals. Huh... That's really weird. I started it again and I could smell something "plastic like" burninng near the alternator. I stuck my nose down there near the alternator and i could smell it even more and I could feel the heat coming off the alternator as well. The alternator was smoking hot... I couldn't even touch it. This was after just a few minutes of running. I used my lifeline... Called a friend who is a Pro mechanic and ran this scenario by him. His answer: Duh... Your alternator is toast! If you unhook the power cable from it, your problem will be solved immediately. He was absolutely right.

I've been working on cars all my life. I've never heard of an alternator doing this - Dead short, killing the battery and everything that goes with it. The car was completely dead and it could not be brought back with a 100 amp charger. Even with the charger on high, the charger could not overcome the shorting out of the alternator.

I've seen this same set of symptoms posted on Cobalt forums all over th place with no one seeming to come up with a solution. I hope this helps another Cobalt owner. The fix is pretty easy (test it first by disconnecting it though) Swapping out the alternator is about a 20 minute job and the part is $150-$350 depending on whether or not you go with a rebuilt or a new one. Rockauto has a new AC Delco for about $230 with no core charge. Not cheap but not horrible either.