[Loaorndnam]

So a while ago, I started feeling a vibration in my steering wheel when I was in the bottom of hills. The vibration would occur when the engine was running at about 1500 RPM. Sometimes it will only last for a second, but other time it can last for longer. The vibration will stop once I come over the top of the hill, or I can accelerate out of it. At first, I thought the problem was the A8 torque converter problem caused by GMs original transmission fluid. However, when I took the car to the shop they told me that the previous owner had changed the transmission fluid and when they took it for a test drive; they could not find any symptoms of a bad torque converter on their measuring tools. I’ve also ruled out that it does not have to do with the cylinder deactivation. Another thing I find to be weird is that after the car has been taken for a longer drive, 1+ hour, the shudder seams to disappear for a while. However, it comes back after a couple of shorter drives.

So my current thought is that it has to do with the flexplate maybe being cracked, lose or bent. It would be much appreciated if anyone have any thoughts on what is going on?