We have a 2000 Cadillac Catera the Radiator has

You blew a head gasket no way a new radiator will fispx this issue !!!!!!!!

Sounds like the head-gasket blew and allowed oil into the coolant and coolant into the oil. Unfortunately, it's time for a tear-down and rebuild of the engine.

Dont flush untill you have removed the heater control valve because it has a piston and diaphragm setup vacuum on the line will cause the diaphragm to expand and not close causing the valve and hose to fail no matter how tight you clamp it. heater control valve is located at rear of engine bay passenger side near heater core hoses.

replace your thermostat ,check the hoses ,radiator cap and if problem persist then is your water pump ,it will be a big problem if you don't take care of this first.cause running a vehicle hot can blow your head gasket and is gonna be a whole new ball game good luck

This is what you get when water and oil mix together, your most likely cause is head gasket failed
Hope this helps
Steve

Hello: The oil cooler is not in the radiator. The oil cooler is under the intake manifold which has to be removed to replace the oil cooler.

Oil cooler under the intake plenum at rear top of engine is either bad or the gasket is gone. If you take oil filler cap off, you will see the paste on the cap. Are you going through coolant every so often?


Same as on my wife's 01.

it is normal to have that paste stuff on the underside of your oil cap and some on the tube the cap goes on. this is condensation it goes to the highest points in the engine alot of short trips makes this worse
if the oil thats drained out looks like regular dirty old oil then dont worry about it
if it looks pastie white then you got trouble

I don't have a diagram, but your problem is the oil cooler underneath the intake on top of the engine. Remove the intake, and the cooler is right there in between the heads. Easy to change once you get the intake off. This is a VERY common problem on Cateras, and the symptom of it is oil in your coolant. I have a 1998 Catera and had the same issue.

Red oil, radiator trans cooler has failed....Brown oil, iether intake or head gasket has failed...do not drive car...have it towed to a shop .