into the fuel system and causing blue smoke to come out of the emission pipe. We were told it would take $2200 to repair it. They also said since it is a BMW they recommend the engine be replaced since it is so difficult to take apart and piece back together and that would be around $5000 or more! This car is the most comfortable, easy, smooth control in any road condition as it is all wheel drive I have ever had. I don't want to sell it but don't know if replacing engine is worth doing.