Black sediment in coolant
I just changed the thermostat, housing, upper and lower radiator hoses and when I drained the system I had a black sediment in the coolant that I drained. I'm guessing that it is from the hoses breaking down but not sure?
The vehicle in an 05 WK 4.7L with 120K miles. I did a flush and refill at 105K miles so the coolant is relatively new. The water pump was replaced at 70k miles and I reused the coolant that I removed. They are the only two coolant related maintenance that has been performed. Any thoughts on what the sediment is???