[fifcic]

Hello.
Like a lot of other people in this forum, I have got the Torque converter stuttering issue. I took the car to the dealer and was told that my torque converter was part of the defective ones noted in the SID #44470. I had the clutch plate machined incorrectly issue. They are replacing the torque converter. Note my car was made in February 2016 and has about 24000 miles. it is a V6 A8.

This got me thinking. Since I got the car, I experienced a loud growling sound coming from the engine when accelerating in 3rd or 4th gear. It would happen randomly. This issue has been reported in this forum by others but I could not find the original thread from a year ago that had a video showing the growling sound.

I think the growling sound is caused by the engine lugging and the sound being amplified by the Noise tube connected to the firewall. The reason why the engine is lugging is because the Clutch Plate in the torque converter is stuck engaged even after the computer send the command to dis-engage. This result in the engine trying to accelerate while in direct drive at low rpm (low torque) and lugging. The Trans Computer will not throw a code as it has no idea the clutch plane is still engaged. Another thing is that the trans computer will not allow downshift on the paddle because based on its programmed torque curve this is the right gear (if the TC is working properly).

So my advice is that if you are experiencing the engine growl when accelerating at low speed and low RPM, you might have a bad TC with the clutch plate not always unlocking when commanded by the transmission computer.

I might be wrong. I am not a transmission specialist but I think this would need to be investigated.