I had a mechanic give me that.. "if it isn't happening when we look at it we can't fix it" poop once.. I told him to give me his home number, 'cause I was going to call him from the back of beyond at 3 am when I was going home from work at the hospital and the danged thing died again. (Bloody car was only a year old, and I TOLD him what was wrong with it.) Guess what.. took it in, they fixed what I told them was wrong and I never had a problem with that part again.. worst lemon I ever had...hmmm, also the most expensive car I've ever had.
Go figure. Good luck darlin'.