need help with m20 cylinder head

I recntly had some overheating issues with my 89 325i. I was losing water and had signs of oil in the water and then milky oil on the dipstick. did the whole top end as wellas timing balt and water pump. was fine for a couple of days and this morning I had water in the oil again. I'm not getting any smoke and as long as I'm moving it runs cool. I didn't notice any cracks in the head at all.