hey, i just found out quite alot of oil is leaking into my coolant and i was wondering if you guys could help me out by telling me what you guys think. Ive taken the car to a mechanic and they reckon it could be either a cracked head or a crack in the block, both these are an expensive option to repair. Would it also be possible that the head gasket may have something to do with the problem? eg over tightning etc..