What else could be wrong?

Check this YouTube video out. It is a common Cobalt problem https://www.youtube.com/watch?v=EzQZbGp14ro

If that is connected okay.... then have u noticed any leaks coming down from the water pump. That would be my next guess

I don't know where he water pump is exactly. I don't have a whole lot of leakage. It'll steam a lot, but it doesn't smoke and that comes from the overflow tank.

Your cooling system needs to be under vacuum...otherwise it will boil. Let's try an inexpensive fix next.....replace your radiator cap at AutoZone.....they will do it for u...no cost, if you ask. Should cost between $3.00-5.00

The water pump usually leaks from an old seal or the bearing goes bad....and the car keeps overheating. That would be the next thing to check after placing a new radiator cap on it

Are you talking about the overflow cap? I tried that last night as well. I'm supposed to be having it towed to a show tomorrow. I'm just a little nervous that it's gonna be a head gasket.

There is a cap on the radiator that must maintain vacuum. There is a cap on the plastic overflow container....no need to change. If it is the head gasket.....then u will notice white smoke in your rear tail pipe. That is the first sign

As you are driving and the car overheats......have u tried turning on the heater to max? That usually kicks in some cold water//antifreeze and may give you a few minutes more driving before you should stop. If that water temp needle is in the red.....then pull over....don't drive. You will be adding more cost to ur repair

I just had a shop replace my radiator, as far as I know there's no way for me to get to it without removing the entire thing. There's no smoke coming out of the tail pipe. I don't have any heat. We bypassed the heater core because it wasn't giving me heat.

Have you purged air out of the cooling system? There are good videos on this subject on Youtube. Your radiator actually operates under pressure, not vacuum. Try adding some Water Wetter by Redline which should reduce the operating temperature noticeably.

I haven't, I assumed the shop had done all that.

What shop did u take it to? You can narrow down to a certified shop.....such as AAA roadside service....u need a membership. If I am ever broken down....they tow and have a current list of AAA certified shops. They work hard to get this accreditation. Just in case you are not happy w your current shop.

We used my boyfriends moms shop. I'm having AAA tow tomorrow, but it's not my membership.

It's okay.....make sure u get their recommendation for a AAA shop....even if it isn't ur membership...u can still use the shop....they are more honest, and less likely to be ripped off

No disrespect to ur future mother in laws shop.....they may just specialize in foreign cars.....or Mercedes Benz's. They may not know about Cobalts.

You have two problems - your car and your future in laws.

You're not wrong about my future mother in law. Haha I'm having it towed to the same place that changed the radiator. I'll find out if they burped it, if so then I guess we go for round two. I've never had an issue my dad hasn't been able to fix and he's stumped. Unfortunately this is getting really expensive and I'm running low on money. I just hope whatever it is isn't going to be crazy.

Good luck with your problems. You may have to have a pact of silence with the BF when you take your car for service at another shop.

Is this auto shop a place that your BF's mom just uses....or is it her own shop that she runs!?!

She just uses.