Oil in radiator

i own a 2003 cts i started with it telling me I had low oil pressure, brought it in to the mechanic they changed a oil censor, had no problem with it telling me oil presssure low, now i have a problem coolant light came on, checked it I had oil in my over flow jug, added coolant and it overflows, back at mechanic they told me its the oil cooler that bad, can u change oil cooler and flush out radiator and hoses and waterpump with something? or do u have to change the whole cooing system like waterpump radiator, hoses and ect,

They can flush the cooling system with a detergent to clean out the oil contamination. If the oil cooler is in the radiator, just replace the radiator. It will come with a new oil cooler built in. If it is similar to the 1999 design, the oil cooler sits in the ‘V’ under the intake manifold in a bath of coolant. There is a GM kit to replace this cooler.

If it is just the oil cooler, and it is replaced the rest of the cooling system can be flushed out and refilled.

The oil cooler and radiator might be so integrated that you could need to replace both. The rest of the cooling system is fine with flushing and refilling.

thanks u was it getting in the radiator when they changed that oil censor that was leaking? can the oil get in the system with that when it was leaking the oil censor?

Doubtful. The sensor is attached to a port, usually in the engine block not near the coolant jacket. GM has had issues with leaking sensors before. Also had issues with leaking oil coolers.

Personally, I believe that oil coolers are a product of over-engineering. There may be some benefit to race cars ad ultra-high-performance cars that are used for continuous performance driving, but for regular street cars used in daily commutes or typical travel at standard American highway speeds, I see no benefit. Just another pricey repair to be made at some point.

THANKS FOR YOUR ADVISE… IT WAS VERY HELPFUL…