I woke to find antifreeze all over the driveway. My reservoir was empty. I took it to the radiator shop and they said I had to leaks. Then I remembered I had the warranty so I took it to the dealership, and all of a sudden I don't have any leaks. Long story short, I think the dealership put stop leak into radiator.
Is there a way to tell if they fixed the radiator vs. putting stop leak in it? For example, if they put stop leak into the radiator, would I be able to tell visually by looking at the antifreeze? Mine has black white grayish powdery stuff and I'm wondering why.