My '08 TL base model with auto trans is recently started making a metallic crackling/rattling noise that occurs during only while accelerating and only through the first few gears. The noise goes away (or at least diminishes to the point that I can't hear over the sound of traffic) and the noise occurs only in gear, and not in neutral or park. I have checked the every heat shield and none are loose. A month or so ago, I had my timing belt tensioner replaced, and I have only noticed this noise since then.

The shifting feels much sloppier, the swift acceleration seems delayed, and the overall performance seems diminished. I have owned the car since August, had two previous owners and appears very well cared for given the detailed service records kept and clean history.

My research on this forum into transmission issues led me to the pressure switches and transmission fluid swaps, however I would think the switches might explain the poor shifting but not the noise, and the transmission fluid is like-new.

I have had no issues with the car until the timing belt tensioner began making (a completely separate) noise which was fixed by the repair, so I am hoping that somehow this is related and not simply my transmission on its way out.

Any thoughts or suggestions are greatly appreciated.

 

Change trans fluid. See if that helps. Go with dw1 3x3. If you change it and brakes or goes out, nothing you do will stop it from happening. Just my 2 cents. Your 08 aswell as the 07 have the updated trans. Still glass, but not as bad.