Coolant Leaking problems of the 2009 Nissan Murano

I am the 'second' owner. The vehicle was gifted to me by my son. It passed the autocheck vehicle history report. I received the vehicle 5/11/13. Failure mileage is approximate. When starting engine huge amount of white smoke exits the 2 exhaust pipes engulfing entire vehicle. This happened continually every time I started engine. Contacted Nissan consumer affairs directly & was referred to dealership. My son spoke directly with dealership service department. The required 30,000 maintenance was performed. After 1 week dealership recommend new engine. I was 6 months past the warranty date, but Nissan refused to honor it as I was a second owner. Per my son's instructions dealership removed spark plugs to soak tops of pistons. Let soak over night. Performed a leak down test to find all the cylinders with 60% or more leakage from rings and valves, removed oil & performed 2 engine flushes, cleaned all oil out of intake maniford, reinstalled plugs, changed oil again, performed multiple road tests. Preceding service included replacing engine air filter. Performing idle learning procedure. Fuel system serviced, cleaned fuel injectors & throttle body. Removed all build up from throttle chamber & plate. Performed fuel system service and 6 cyl tune up/6 22401-ew61c plug-sparks. Serviced complete coolant system. Serviced automatic transmission, exchanging fluids in case up to 6 quarts. Performed front & rear differential fluid exchange. Dealership kept vehicle 3-4 weeks, however problem still exists although intermittently.

Vehicle was in shop for major (60k) maintenance. Inspections showed some leakage of coolant from top of engine, diagnosis confirmed as leaking head gaskets. Have pursued complaints with Nissan dealer and Nissan consumer affairs. This is a major defect requiring expensive repair if not corrected could lead to engine overheating and failure.