Help oil in coolant.
 

Help.my 2008 as has oil in the radiator. Just changed thermostat. Still runs hot 210+ no steam from tailpipe. All my oil went into radiator in just 6 miles and out the overflow.what's wrong?

I'd guess oil cooler.

Or head gasket, but oil cooler could be the culprit!

didnt the 2008's have problems with the blocks? something about them being porous blocks, cant promise there is any kind of recall but may be worth checking with GM on it

Get a kit from your auto parts store that tests for "Products of Combustion" in the coolant, and also pull the plugs when the engine is dead cold to see if one looks "steam cleaned". If the plugs look OK, and the test kit shows no combustion gasses in the coolant, then cast a suspicious eye on the oil cooler.

And do a compression test/leakdown test while you're at it just to make sure.

All HHR's, be they 2.0, 2.2, or 2.4 powered, need careful and thorough investigation of any coolant contamination in the oil. Ecotec's are known for head and head gasket failures, and contaminated oil will kill an engine deader than dead in short order.

Porous cylinder blocks
 

Yes the porous block issue does exist. The casting problems i had with my car was coolant leaking through the cylinder block and dripping into the oil pan. One cup of coolant every 60 miles. The engine was replaced under warranty in 2010 on my '08 SS.

And... did 2008's have oil coolers?

All the SS's do have them Don.

I think the head gasket is most likely. The car was 7 years old.
Jefferey Mariner, you spent the diagnosis? Do you know the reason?

Well
Freedom for freeman :smile: