But if you’re in the market for a 6. Power Stroke and you want to avoid developing pesky maintenance issues or paying for repairs, your best bet is to search for a 2015 or newer model and avoid model years 2011 through 2014. Power Stroke Engines While the 6. Power Stroke is known for significant issues like high-pressure oil system failures and head gaskets, he notes they can be made dependable with proper upkeep. In stark contrast, the 6. Power Stroke is identified as the most unreliable in his experience.But if you’re in the market for a 6. Power Stroke and you want to avoid developing pesky maintenance issues or paying for repairs, your best bet is to search for a 2015 or newer model and avoid model years 2011 through 2014.