ive just had my car serviced today and found out that the oil sump is knackered. vauxhall told me that the threads were cross threaded and i would need a new sump costing £200 . i then went to a private mechanic who told me that it was very hard to cross thread them and it was more likely that vauxhall had damaged it and want me to pay for there mistakes. he also said that if the sump was already knackered then oil would be dripping on to my drive. but it hasn't. so can anyone answer me a couple of questions
1. is vauxhall right about the cross threaded threads?
2. is my mate right that there would be a oil patch on my drive if the sump was knacked before the service?
can anyone help as i have the car booked to be fixed tomorrow and would like to be able to go there with a bit of knowledge if they give me all the mechanical crap