2007 buick lexerna 3.8 ticking from top backside of motor lost power overall and ticking is constant

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. It is difficult to weigh in on your concern because I can't hear the noise and I can't check the engine for performance concerns. Engine noise itself is not enough of a fault to cost performance issues. There could be an internal engine wear issue, but that doesn't always lead to a loss of power. This sounds like something that needs to be a evaluated by a technician near you who can listen to your concern and also weigh in on the lack of engine power you are speaking of. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.