My engine has very low miles on it for starters. It's in a street rod that usually gets driven in the Spring and Summer. I recently had it out a few times on the sunny days to keep everything moving. Outside temp was around 45' F. I went to change the oil and noticed a white foam under the oil filler cap and under the PVC valve. I changed the oil and wiped everything clean and took it out for a short drive. After awhile I checked it again and the white foam came back but not as bad. I noticed moisture droplets starting to form. They were very clear at this stage (no antifreeze color) Because the engine is very open I can't get the temp to climb past about 150 to 160 unless I am idling for a long time. This never happens in the warmer weather. Is this likely a problem due to the cold weather and I'm not getting the top end of the engine heated properly for long enough? I run a 185 thermostat and I have an electric fan that I control when needed. The oil I use was the top product from Mopar and I changed to Ford's best and it didn't seem to help. Thank you.