My radiator burst on my is200 had a new rad fitted it drove fine for a while but is now pressurising up, is this the head gasket needing to be done or do they suffer with anything else. I have spent so much on this over the past few months and was planning to sell it, but now dont know what to do, if i was to sell with needing the headgasket doing what would it be worth? its a v reg done 137000 miles mot'd til next feb?