My car has been over heating. we changed the water pump, and themostat. performed a radiator flush (twice). water was very rusty the first time and a little clearer the second time.

Could be your blend door is not opening all the way on heat,here's a link to look at.

If both heater hoses are getting hot, the problem could be a stuck blend door under the dash.
If only one hose is getting hot, there is a blockage in the coolant flow somewhere.

milky oil means water is mixing with it might be a gasket

if the thermostat has not been replaced i would do this, also while doing this flushed the radiator system out, is also best to back flush they system, also when was the last time the water pump was changed, as over time the fins on the water pump will deteriorate and cause overheating problems, with a/c it will help keep the engine cooler, but you need to check that the parts ive said have been done as this is the main cause of the engine over heating, you will probably find the thermostat is not working properly and there is rust red water in the system, and rusty parts in the emptied water thats why you will need to back flush the engine youtube back flush engine, top up with new antifreeze recommended for your area and engine. and bleed out the air from system. if the water pump has not been replaced in 5-10 years it needs changing.

You may have a blown head gasket. They can leak outside the motor, inside the cylinders (causues white smoke), or into the block causing water in the oil (light brown color and or bubbles on the dipstick) or oil in the radiator. Hopefully you have none of those, so the next step is a radiator flush as you probably have something clogging up the radiator or thermostat. You have to drain the radiator and fill with clean water. Pull out the thermostat and leave it out for the flush. There are radiator flush products that I suggest highly. Run the truck to operating temp (about 20 min) with the heat on and dump the system by removing the bottom hose hose from the radiator, after the truck cools off. With the hose still off dump water through the radiator to clean it out fully. fill with water and let it run once again to clean the block, then reinstall new thermostat and anti-freeze. This should clean out any rust and stop leak that is causing your problems.

Rusty is from running a bad or no mix of coolant. (PH level is off) You may have a water pump that has corroded impellers, and can't move the coolant as well any more. I would start by making sure to flush the engine block again, and make sure you flush water through every possible hose, and where you can get at it.

Why was radiator replaced?Did it have heat before ? If it was plugged, the heater core may also be plugged. Try flushing it with a water hose in both directions. I dont know why the botton radiator hose would be cold, the radiator should be a uniform temp and the air coming through the radiator should be HOT, when the engine is at operating temp. What condition was the old coolant? if it was rusty, the water pump may have lower flow than normal.

There are a number of things that one needs to look at. Make and year? Miles on the car? was the water that you drained from the radiator really rusty or clear? If rusty a back flush may ,"may" be needed. When does the car heat up? At idle after driving it...on the road at hwy speeds....does it heat up quickly or take awhile....etc. Does the car have thermostatically controlled fans? If so are they functioning properly. Have you left the radiator cap off the radiator and started the car alowing it to reach operating temp and looking in the radiator to see if the water is flowing? If the car is old and the water was really rusty it may be that the radiator is partially pluged. Hope this helps. Texas Street Rodder

try to flush the radiator it might be clogged ,,or could be the water pump

The rust is probably in the engine. There are many little pockets, water ways, water jackets (around the cylinders), etc, so getting all the rust out without dunking the block and heads in a cleaning tank is about imposible. I would recommend giving it really good flush every 4 to 6 months. I would try flushing the radiator before replacing it because it is probably not rusted, even though it is full of gunk.