Excessive Oil Consumption (Blue, Gray Or White Exhaust Smoke)

Incorrect type or grade of oil. Drain and fill with specified oil.
Extended oil change intervals. Change oil as recommended.
Clogged air cleaner element or restriction upstream of compressor. Repair as required.
Engine wear (piston rings, valve guides). Repair as required.
Turbocharger oil seals leaking. See TURBOCHARGER INTERNAL OIL LEAK TEST under COMPONENT TESTS.
Injector or injector "O" ring leaking. See appropriate SELF-DIAGNOSTICS article.