When trying to determine the source of vibrations at idle in my 98 Mazda 626 GF 2L one thing I've found mentioned by many people is a potentially worn out / failing torque converter. However, when researching the matter in the relevant Mazda workshop manual and in the ATSG manual for this specific transmission, neither one of them mention vibrations as a symptom of torque converter problems. However, they both mention excessive noise from the transmission while idling as a potential symptom of such problems.
The closest conditions mentioned in the ATSG manual are:
- Noise severe under acceleration OR deceleration, OK in park, neutral or steady speed
- Noise in Park or Neutral - does not stop in Drive
It's similar in the WSM, but vibrations aren't mentioned anywhere.
So are vibrations, without noise a potential symptom of torque converter problems and of course, if so why?