The other day I smelled the typical "anti-freeze" odor while unloading my 2010 HHR LT w/2.2.
Then I noticed the right front wheel was slinging an oily substance.
Upon further investigation I found a small oily puddle in the dirt.
I promptly put it up on the rack and the underneath was coated in oil and in some "drips" that were formed and waiting to fall there seemed to be water.
I started the engine and within a minute there was transmission fluid literally running out of a hole in the top of the coolant reservoir.
Questions:
#1) Do you believe (my assumption) that the radiator/tranny cooler has failed internally?
#2) (assuming my assumption is correct) What is the best way to flush the transmission without taking to a shop?
#3) What is the best way to flush the cooling system? Because when I opened the drain port on the radiator I got maybe a cup of water before transmission fluid came out and less than a half gallon total fluids......(that in itself scared and stumped me). It has never overheated or presented any problems till this event. Now I want to make sure I "get-r-done" correctly.
I am no mechanic but mechanical enough to do nearly any/everything on a vehicle that doesn't require a danged computer.
All help, directions, instructions, advice are GREATLY appreciated!!
Thanks!!!!

 

UPDATED!!!
After removing radiator, filling the coolant portion with water and pressuring the transmissions portion I have verified that the radiator is bad!!!
Now answers to my other two questions would be greatly appreciated!!!

 

#2. Can't help you with that.
#3. https://www.chevyhhr.net/forums/ss-s...lant-ss-57387/ Be sure to read the edit that starts the thread. Also, this procedure is for the SS model, so some things on your vehicle may be a little different, e.g. the water pump drain bolt may be harder to get to on your engine, and the capacity will be different. If you choose to open and drain from all 3 locations, as recommended, read through the how-to and use only the applicable steps. Make sure to burp the system!! You'll see in the how-to that getting only 1/2 gallon from the petkawk alone is normal.

If unsure, please ask questions, the cooling system is too important to take chances.

 

Welcome!

The "best" answer to both questions is a shop. They have equipment that can flush each system completely. ATF and coolant don't mix, so they both need a good flush, not change. Sorry.

Evidently your trans cooler has a hole in it. A possible way to avoid the cost of a new radiator is to block the ATF ports of the radiator and install an external ATF cooler.

 

Both very good points, donbrew!! Perhaps a shop can run a mild detergent through if necessary.

 

I am replacing the radiator. I want to flush both systems as I know the tranny fluid will definitely not be good on parts in the cooling system which are not of a metallic material. I just dropped the trans pan and was pleasantly surprised to not find any water in the pan and only a few drop in the filter when removed and turned over to drain. A bit of a relief to be honest for I really expected to find a pan full of coolant. Especially due to the amount of trans fluid in the cooling system. But knowing that the pressure in the trans system is higher that the cooling system I feel I got a bit of physics luck on my side LOLStill want to flush both systems before I install the new radiator in order to avoid contaminating it.
Thanks again y'all. All info much appreciated!!

 

Update:Taking to the shop is out of the question. Already 1/2 way through this.

 

When you just drop the pan that leaves about a gallon of ATF in the converter.

I don't think drops of ATF are going to hurt the cooling system, it is lubricant after all. However, coolant in the ATF could cause big problems!

Remember DEX VI, the expensive stuff!

 

It's not drops of ATF in the cooling system...........
More like 60% of all the fluid in the cooling system was ATF.
I drained the radiator and got more ATF than I did actual coolant.
Only drops of coolant in the trans filter.

 

And use Dexcool and whilst your hands are dirty a new AC Delco thermostat!