Overheating & recent symptoms
 

I have an '06 HHR Spring Edition. About a month ago, I began to notice a bubbling/gurgling noise behind the dashboard. Didn't think much about it and continued using my car normally. About a week later, as I was driving, my temperature light flashed and the needle was in the red (I don't remember what temperature the coolant read, but I'm guessing around 250 degrees, give or take). I stopped the car and waited for it to cool, and I noticed a sound like a fan running after I shut my car off. I took it to a shop the next day, described the problem, and they suggested a coolant flush. I know very little about cars, so I decided to trust this person. Once the flush was done, they told me that I had no leaks, everything looked good. My car ran fine for about two days after that and started overheating, especially while driving at interstate speeds. I took it back the the same shop, they looked at it again and told me that I have a leak somewhere in the front of the car, either the front main seal or the water pump. I didn't get the car serviced then, had water added to the radiator and left. Since then, a friend and I identified the source of the leak, which is coming from the coolant recovery tank. It is the ONLY visible source of a leak that we could find. Currently, my car gets hot when idle, but cools as I drive, especially at interstate speeds. I have ordered a replacement recovery tank and will replace it myself.

I apologize for such a long post. Based on these symptoms, what can I do to narrow down what the problem is? Could the recovery tank have anything to do with the engine overheating? Thanks in advance.

Welcome to the site, if the recovery tank leaks it should only leak what's in the tank!
I would suggest to replace the thermostat if it is original it's 9 years old.
The gurgle under the dash was air in the system going thru the heater core.
The fan would be your rad fan it'll run after you stop the car and turn off the key.

How does the coolant look?

If you just had it flushed, I'd imagine it should still be pristine.

Does it leak more as it heats up?

I'll take a look at the coolant as soon as I get home. The only time that I saw a leak from the coolant recovery tank was when we added water to it.running the car until it warmed up did not seem to have any effect on the leak.

No leaks that they can see. I know on my Silverado I had, if it wasn't running there was no pressure, therefor, if it is not running a leak cannot be found as easily. My Silverado had a cracked reservoir, and I didn't know it for the longest time, until one morning, it started overheating badly. All the same notifications you got.

If you have a leak and the fluid contacts something hot, the smell will be pseudo sweet, and strong.

My guess, based on what you say, is you have a leak, and can't be seen while the car is off.. Check the reservoir, fill if necessary, and turn it on. Check for leaks. No leak? Drive it a bit, find a safe place to pull into, check it. Leak? If no leak, then I am stumped.

Kevin

Kevin, I will definitely keep a close eye under the hood for the next few days. I am hopeful that the reserve tank is the problem since, thus far, it has been the only visible source of a leak. I think that when I took the car to the shop the second time, they added liquid to the reserve tank and saw it dripping underneath the car, but couldnt identify the source of the leak. If I was able to find it myself, then I don't see how this was overlooked.

Two more things that I forgot to mention...I have recently noticed light steam coming through my air vents, and it smells like it could be coolant. My coolant temperature fluctuates between 189 and 217 while driving. Not sure if that is normal or not, but it never stays leveled out at a constant temperature.

I think you just nailed it with the last posting SamualJ - Steam from the air vents probably means the heater core is leaking. You say you can smell coolant at the same time - that's the tip-off.

When I had a heater core go in my Dodge, it looked like smoke, and the smell was pretty nasty - and I was initially thinking fire/burning wiring. But it turned out to be the heater core. Replacing a heater core yourself is not for the weak of heart. And shops charge an arm and a leg for it.

And nobody thought "head gasket"?

i.e. forcing coolant out of the tank, air in system.

That's where I was going with my question on dirty coolant ;) .

I had a Lumina with this problem. I could go through a whole jug of coolant in a single trip across town.

But with a little fresh oil I drove it 80 miles straight with no problems at interstate speed.

I really hope it's not the heads or gaskets. :(

Perhaps a leak down test is in order for the cooling system, this will confirm a leak and where it is!