Hi Guys I am zero in car domain. I got 1988 Hatchback corolla AE82. Last week i had a problem that car was extremely heat up while i was driving and i realized that coolant was drained out . the mechanic spotted white fumes in the engine oil filler cap , which hit him to check the fan which in reality was not working and he fixed the fan problem. he said to monitor the water level in the radiator for 2-3 days , if it drastically drop then its something urgent otherwise OK. I am checking water level which is not dropping for last 2 days but I noticed there are still white fumes in the engine oil filler cap, can any one tell me what is this and why ? thnx