Sure you can drive it but, you need to ask yourself, why is there oil in the radiator? If you did not pour oil in the radiator then you have a problem. Most likely cause is a blown head gasket. This is extremely serious, and will destroy the engine if not repaired.
Do you need to check two possibilites, one, check if the oil is from transmission or from the engine, if the oil is red,is from transmission and you need to replace radiator, if the oil if from the engine you got it a big problem, because the only way that the engine oil is inside the radiator is because the engine has a bad head gasket, that mean you need to repair the engine heads.
The engine
the thick liquid would plug your radiator and ruin your water pump. and destroy your engine.
If you have odors coming from the engine area you probably have something leaking be it oil, engine coolant or exhaust. If the engine is overheating, a radiator flush may or may not help because there are several reasons why it could be overheating. Take it to a trusted mechanic for diagnoses.
Really need to know the year and engine size. But you can check this, Does your engine have 2 lines just above the oil filter that run up the side of the engine and goes into the radiator on the drivers side ? If so then that is the engine oil cooler lines and the tubes in the radiator were the oil flows through to cool the oil are probley leaking into the radiator coolant. IT happens often. WILL NEED TO REPLACE RADIATOR. And flush out the cooling system real GOOD. Did your engine freeze from lack of antifreeze ? If the radiator fluid is cheery red looking then the transmission cooler that is built into the radiator is leaking. REPLACE RADIATOR. GOOD LUCK.
check oil for water and radiator for oil, if engine oil has water miced with it ,the oil will be milky looking same does for radiator
Radiator, engine oil, trans fluid, fuel line, axle oil,............
You did not say what you are working on, YEAR AND ENGINE SIZE. But in most cases or designs the water pump can not leak oil into the coolant. The water pump has nothing to do with the engine oil. Does the engine have a engine oil cooler on it ? That would be 2 oil lines just above the oil filter that runs down the side of the engine oil pan a go to the radiator. There are tubes inside of the radiator that oil flows through and they are none to leak oil into the engine coolant that's inside of the RADIATOR. If they are leaking then REPLACE RADIATOR. BUT like I said I don't know what you are working on. Would like to help you with your problem, But need more INFO. NEUTZ.
Sometomes it is hard to get all of the oil out of the cooling system. However the place that replaced the engine should flush the cooling system until it is clean. Also if your car has an engine oil cooler , it could be the cooler in the radiator and not have been the engine in the first place.
At the front of the engine on the bottom in front of the engine about center of car just behind the radiator. Accessible only from underneath the car.
Oil in the radiator is a sign that you have a blown head gasket. The head gasket will have to be replaced. STOPdriving this car immediately or you will destroy the engine.