Chilly PCV spits oil
Some 2005-2006 Ford Five Hundred or Freestyle or Mercury Montego vehicles that are not equipped with an electric heated positive crankcase ventilation system (PCV) valve, may exhibit engine oil leaking from the engine dipstick tube in ambient temperatures below -20 degrees Fahrenheit.
Remove the original PCV valve and hose. Install the Heated PCV Service Kit, following the instructions included with the kit. The heated PCV kit is available as P/N 5F9Z-6A666-A.