I seem to have the same problem with my crossfire I have taken it in several times and never can really find anything, a few time is said something about air flow but when it was checked again couldn't find anything wrong with it, and this has been going on for the last 3 years, starting to get to be a bit much to pay to have someone look at it and they can not find the problem if anyone really ever finds out for sure let me know.. Mostly happens when it rains or with a big change in the weather..