One problem related to engine cooling system has been reported for the 2004 BMW X3. The most recently reported issues are listed below.
August 1, 2010 took car to local BMW dealership northpoint to have air conditioner checked prior to 100,0000 mile warranty expiring. Told by dealership could not repeat diagnosis of why air was not cooling. On 11-15-2010 at 107,215 after warranty has expired a 3rd party diagnosed car as needing a evaporator coil which is a $2000-$2500 replacement. In addition to another problem of the engine burning and leaking oil which is $6000 to replace.