OK - this has never happened before so I thought I would post this to see if anyone else has had a similar issue. I have a 2007 MCS with 45000 miles and the oil is changed every 4000 miles. Today I checked the oil and noticed that it could use topping off, when I went to remove the oil cap it unscrewed normally but would not come out. I cannot see or hear any damage/cracks to the cap so I am a perplexed at the moment and open to suggestions

Thank you in advance.