THE DURAMAX ENGINE INJECTORS GO BAD AND SPRAY TO MUCH DIESEL AND IT FILLS THE CRANK CASE UP 200 THOUSAND MILE WARRANTY COMMON PROBLEM DON'T DRIVE IT ANY MORE IF U HAVE BAD INJECTORS.
May be totally unrelated but I had the same issue on a 95 civic. It has "spark plug seals" that needed to be replaced. Dealer did it for about $250.
Whoa whoa ... You've said that the car takes 7 quarts of oil. That's 14 pints. Depending on which engine variant is fitted, engine oil capacity is either: