When temperature is bellow -20°C, the PCV valve freeze and than oil get out by the oil gage. The first time it do that Ford made a modification on my car it happened in 1999, the problem was solved for 8 years. Last year I change the PCV valve, so it do that again.
I want to know what is exactly the modification they done in 1999.
What can I do?

Cars & Trucks - Ford - Escort - 1998 Ford Escort