1/2 quart of coolant was in, from engine area. When I returned coolant so much of rust, or whatsoever is that deposit, stay at bottom.

 

Stop feeding it coolant .Where at the engine do see rusty water? If you see rust you need to flush your cooling system follow the list I gave you or take it to a shop. The radiator could be plugging up at the bottom if it is real bad it may need to come out. I would flush it now to see how good it flows and clears up. What ever you do do it before you put in your new heater core.
AIRBORNE 82nd.

 

Again, I do not mind giving to mechanic to flush cooling system. I replaced few days go heater core. This is how coolant looks that is in, and it is 1 year after mechanic "flushed" cooling system. My problem is I will pay again for nothing. I wonder when he replaced the water pump last year if he returned coolant back that he drained to replace water pump. The little yellowish that is visible in picture is from me adding 1 gallon a few months ago when I bypassed the heather core. The new coolant in milk plastic jar looks yellow/green from outside and those that I drained, one gallon, to replace heather core look dark brown.

 

That might just be OAT antifreeze.

 

^^^ Green or yellow should be in. I asked a mechanic this past year and he said he will put yellow in.

 

Yellow is actually Ford's latest stuff. Circa '03 Ford went gold like Zerex G05. Then they started using Dexcool, then yellow

So, ya gotta have a PhD in color identification to recognize gold vs yellow. We can only hope that next maybe they use "bronze"....