hi hope someone can help me i had a couple of guys come to look at my jag to buy ,i had to pop indoors to get paperwork we took the car for a drive and came back they looked over the engine again and this guy tells me i got head gasket problems. cars been fine before he took off engine cover and their is an amount of oil over it then he took of header tank cap put what i think is the same finger and says its covered in oil,now i know the cap would have a paste on it and so would oil filler cap but both are clean but the header tank you can see oil in it any ideas please i do believe these blokes were trying to rip me off.