Is a car dealership liable if they misdiagnosed a problem while a vehicle was under warranty but found the cause after the warranty expired?

Question Details:

I purchased a car from out of state with 80k miles on it in 2008. Upon delivery of vehicle I took it into the local dealership to check out a slight rattle in the car while accelerating. They couldn't find the cause of the rattle but assured me it wasn't an engine problem, and the vehicle was fine. Throughout the years the same dealership has been servicing my vehicle. Last week they found that a bad torque converter was the cause of the rattle but it's now at 104k miles and out of warranty. A service bulletin was put out in 2005 for that exact symptom and cause. Are they liable? Important Notice