If you have a quite a bit of coolant in your oil, the oil will be milky colored and the filler cap will have a milky sludge attached to it with beads of water clinging to it.
If you do not have milky oil then you can test for coolant in the oil by putting some of the oil on you finger and taste it, it will be sweet to the taste.
I know I will be getting some flack about this test from some on this forum, :whistling: but I have found that this works and I have not died yet. Just flush you mouth out will lots of clean water.
If you have coolant in your oil and suspect a head gasket leaking, fill the radiator full leaving the cap off and start engine and watch for bubbles at the filler cap. that should indicate if you have a leaky head gasket. Or take it to your mechanic and have each cyl pressured up and check for leakage. ( Known as a leak down test) Remember that the coolant will only leak into the cylinders when the car is not running as the average pressure in the cylinder is higher than the coolant pressure.
Another spot for a leak is the intake manifold gasket leak, which will leak all the time.
Hope this helps.
