CarComplaints.com Notes: Engines shouldn't need a new quart of oil every 500-1000 miles, but for thousands of Suburban owners that's exactly what's happening. Engine oil consumption on aluminum block engines with Active Fuel Management (AFM) is out of control and owners are left looking for answers.

The most likely culprit is an uncovered AFM valve which, in many cases, can be covered under warranty. The problem is the issues don't stop there and many owners have been told by GM just to buy a new engine. Take one guess who they want to pick up the tab.