See and avoid the new plastic Wix fuel filter for the Dec 03, 2011See and avoid the new plastic (composite) Wix fuel filter for the Duramax - unless you like to limp your engine from air in the fuel. :mad2: Comes from a bad WIF thread/design/whatever - air leak at the bottom of the plastic filter. This is the first time Wix has ever let me down and by the looks of it I am not alone! See Clogged Fuel Filter Symptoms and Diagnose Problems When you apply a load by pushing down on the accelerator you need an ample amount of fuel to provide that power to get 3,000 lbs moving. Therefore, stalling, hesitation and a severe lack of power are the main symptoms associated with a clogged fuel filter. Mechanics diagnose this by taking a fuel pressure test.