It shakes violently and will shut off if driven for a couple of hours.

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. The concerns are you are sharing are not "common" sounding concerns that can be guessed at here -- you'll need a technician near you to duplicate your concern and weigh in as to what is going on. Saying that this happened before and changing the engine was the answer -- is quite a result! Feeling that the ride is rough and then the engine stalls - leads me to wonder truly what is being experienced, as it is so difficult too know from the concern description itself. Hands on testing is needed - see guidance at a shop near you. 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.