62bassman

06 E350 with 128K, runs great, just had brakes done was told by ( reliable- long term ) dealer that I had oil in my coolant found during vehicle check. Had radiator flushed, and advised to check again after 1K. I checked after 250miles and have small amount of oil again in my coolant. Car is running well and getting 25mpg and not overheating but I want to get this fixed. Is it more likely that the oil cooler gasket has failed or that I have a more significant problem and are there any recalls on head bolt leaks?
Also, How much should it cost to replace the oil cooler gasket and should that be the first thing to try?