AFM/DFM Lifter Failure & Engine Knock

Cylinder-deactivation systems (marketed as Active Fuel Management or Dynamic Fuel Management) shut down cylinders to save fuel by collapsing special lifters. When a lifter fails or sticks, it can hammer the camshaft lobe, producing the characteristic tick and, if it goes far enough, destroying the cam. The result is a major internal engine repair on a relatively new vehicle.

These repairs are invasive and slow. The engine typically has to come apart, and owners routinely report their truck sitting at the dealer for weeks waiting on parts. Worse, some owners report the noise returning after the repair — meaning the same defect has resurfaced after a very substantial teardown.

An engine defect of this magnitude substantially impairs your vehicle's use and value, and the extended time out of service often supports a claim on its own. If the manufacturer can't repair it after a reasonable number of attempts, California's Lemon Law may entitle you to a buyback, replacement, or cash settlement, with the manufacturer paying your fees.

California's Lemon Law (the Song-Beverly Act) applies when a substantial defect can't be repaired after a reasonable number of attempts, or when your vehicle has been out of service for 30 or more cumulative days. For serious safety defects, fewer failed attempts are required.

If your vehicle qualifies, you may be entitled to a buyback (a refund of what you've paid, minus a mileage offset), a replacement vehicle, or a cash-and-keep settlement. The manufacturer pays your attorney fees on a successful claim — so pursuing your case costs you nothing out of pocket.