I just changed the coolant in my 96 Miata. First time I've changed coolant myself. Last change was 60K ago. After draining, I put a cleaner and water in it and drove it for about 1 hour. Then, I let it cool, and drained that. Then I put the new Coolant (yellow color) in. Now, less than a week later, the new Coolant is brown. Is this because all the crap that the cleaner dislodged is in my coolant? And, is this a problem? Should I drain and refill it again? Or is this typical and OK to leave alone?
Brian