My daughter has an 09 Aveo sedan with manual trans and 105 K in miles. She's had it since new.

On Friday after about 150 miles of driving, the car began to overheat. Thankfully, she had AAA Platinum and got it towed home.

The first thing I noticed after popping the hood was that there was what seemed like oil in the coolant recovery tank. I put my finger in there and when I pulled it out it was caked with a brownish paste (See photo).

On Monday, she had it towed to an established shop (decades in business) that we have used before. They did diagnosis work over the past two days and they are ruling out a head gasket and said they couldn't make it overheat.

The shop wants to keep working on it. The only thing significant statement they made to my daughter so far was a question -- did you accidentally pour oil in the radiator? (Of course not). That doesn't give me a lot of confidence. Is there something specific to the Aveo that they might be missing? What could this be?

Name: IMG_0651.jpg Views: 11186 Size: 292.6 KB