Hey guys, just a couple quick questions about my 07 cobalt ss/sc with stage II. When i run the AC most of the time my rpms will bounce alot when i try to idle, and if i rev it a bit the rpm will come back down, almost stall, and then bounce back up (lights dim too) ... then there are times im sitting at a light with the AC on and itll just stall.

Also, my AC isnt very cold, the only time i start to feel it cold is when im giving it gas, but at idle and cruising it'll be cool but not as cool as it should be.

Any advice to help fix these problems? thanks everyone

 

If ur gm s2
Clean ur throttle body
Put some new oem spark plugs in. Depending on how many miles r on the car.

As for ur ac
Sounds like it a lil low. Not low enough to kick the safety switch but enough to cause ur cool and not cold problem.
Go to a auto parts store and get one of those ac charge kits...
The fitting is under the supercharger to add the freon..

 

Battery. I had a similar issue

 

My car did the EXACT same thing you are describing. If the problem only happens with the ac on, you have to point towards the compressor. I replaced a condenser once and didnt add oil when I recharged the system. I bought a brand new compressor because it quit cooling after that as well. But, I took it to work and charged it on a robinair system, using the original compressor. I threw 1.5 oz of oil at it, not sure the EXACT amount. But, the car idled and ran WAY better.

You might try just recharging with the do it yourself kit that has oil in it and see. Could save you a lot of money.

 

GM2 07's had issues with the car running with the a/c on. Unless it's hot as hell or I'm cruising on the highway I usually just roll down the windows and deal with the heat because the car sucks so bad to drive with the a/c on.

https://www.cobaltss.net/forums/2-0l...revs-c-280481/

4th post down

 

Its in the tune, and also having a dirty throttle body doesnt help. Then again, you clean it, car runs good, then a month later it begins again.

 

Thanks everyone...so it seems the two things I should try from this post is:

1. Clean my Throttle Body
2. Re-charge my AC (shouldnt be a problem my father is a HVAC guy for over 30 years haha)

THanks again ill let you know how this goes