A few days ago, we published a report highlighting the valve lifter issues some General Motors customers were experiencing in certain vehicles equipped with either its 5.3L V8 L84 gasoline engine or 6 ...

GM Authority has received a growing number of emails and messages from General Motors pickup truck and SUV owners experiencing valve lifter problems. To note, the naturally aspirated 5.3L V8 L84 is ...

When General Motors launched Active Fuel Management (AFM) and then, Dynamic Fuel Management (DFM), the idea was that the fuel consumption of truck and SUV owners could be improved by turning off ...

Noisy tappets (also known as hydraulic lifters) are relatively common on engines that have done their fair share of work. By using oil pressure generated from the engine’s oil pump, the hydraulic ...