Alireza

Thanks Paul for the response. So do you think the water level drop is normal?

Hello Guys, I have recently bought a used 2015 Titanium energi, and the previous owner drove it for 61000 Miles. I noticed that there is some amount of milky stuff under the oil cap. I am living in Davis, CA and as I am student and Davis is a small town I may drive it for around 20 Miles per week and some days it stays off in the parking that is an open area. Since I have bought the car, the climate temperature has been around 40 to 55 degrees. When I noticed the milky stuff for the first time, I checked the water level of the engine coolant system and add water right to the MAX marker. I kept noticing the milky stuff until I had a 160 Miles trip in one run after that trip I checked the oil cap and boom nothing was there and for the following days I didn't notice milky thing anymore. I thought that the dealer washed the engine and some water leak into the oil tank and it was vaporized out. However, after about two weeks of not running the car due to holidays, I ran the car for about 100 miles and again found milky stuff under the oil cap. I checked the water level and noticed that it dropped about 0.5 inch since the last time I added water to it. Do you think this amount of drop in my water level is natural in about 400 miles of use with the pattern that I am using the car? Otherwise this water is leaking to the oil tank and I should seek engine repair? I have never noticed any OMM notification or alarm from my car regarding heat or anything else. I would appreciate any help to diagnose the real problem. I don't know if I should have started a new thread or followed the following thread which has almost the same topic but it is quite old? https://www.fordfusionenergiforum.com/topic/4583-residue-in-oil-cap/