Good evening boss how r you

Dear Sir
Welcome, and thank you for trusting us
when the oil and water mix in  hyndai sonata 2012 that's mean malfunction  engine hood gasket  or in engine hood .
and to solve the problem you must : 

1. check the engine hood 
2. replace the engine hood gasket 
3. replace  engine oil 
4. replace coolant water 

I hope my answer was helpful, please let me know if you have any follow up questions. If you feel I've answered your question already, please rate my answer from top of the page. Your feedback helps to ensure only the best experts are available to help you.
You can also ask questions of our other specialists in the areas of nutrition, therapists, IT specialists, medical doctors, and many more.
We are privileged to communicate with you, and you can always consult many experts on Jawabkom like Doctors, Nutritionists, and Engineers
Kind Regards
Engineer mohammad