Odds are you have blown a head gasket and the antifreeze and oil flow share the same gasket. As the gasket wears, the antifreeze mixes into the oil and vice versa! I suggest replacing your current antifreeze and do a full flush. Test it for a few days and test if you have oil again. A tell tell sign of a blown head gasket is black smoke (burning oil) or white smoke (burning antifreeze ) coming out the exhaust.
if you have tansmission cooling lines or oil cooling lines that go into the radiator, the cooler in side might have a hole in it.
It means that your engine oil is mixing in with your radiator fluid. You probably have water in your oil too. I would take it in and have it fixed.
the thick liquid would plug your radiator and ruin your water pump. and destroy your engine.
If it's just blowing out when you start it you probably have a cracked head or blown head gasket. If there is oil in the radiator there is a change you have oil coming in from the transmission cooler. But there would have to be a lot of oil to make antifreeze come out the radiator cam. Since you did not mention oil I would suspect the head gasket. If you got it hot I would lean toward a cracked head.
sounds like you have a cracked head or cracked block.however, i would check to make sure it is not transmission oil and thereby ruling out a radiator problem
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.
the cylinder head has damaged the oil from the engine going to radiator
Oil in the radiator is usually an indication of a leaky head gasket.
If there are lines coming from the transmission to the radiator, it has a cooler in the radiator. If there are lines from the transmission to an external heat exchanger, that would be an auxiliary cooler.
Bad Head Gasket. See a mechanic ASAP..