4L60E in the Envoy that recently started whining, perhaps more like a fuel pump if I were to describe it. It doesn't happen when you first fire up in the morning, but when the transmission fluid warms up a bit, a tad over 100 F, and you lightly hit the gas taking off from a standstill, you hear the whine right away. You hear it under light acceleration from a standstill, as well as in in park or neutral. From a standstill, you can hear the whine going up to 2,500 rpm, after which it seems to disappear. As it whines in P or N, the whine disappears right away if you slap it in reverse or any other forward gear.
The unit has 115,000 miles on it. It's had very regular fluid (Dexron-VI with LubeGard) and filter (ACDelco TF-289) changes - a drain and refill every 6,250 miles and a filter replacement/pan drop every 25,000 miles. I have a Derale cooling pan, which an extra 2 quart capacity and drain plug. The reason I use a TF-289 shallow pan filter and not the 24208576 deep pan filter is because this particular pan has big cooling tubes, and you can't bolt the pan back on with the deep pan filter. The fluid is always a nice cherry red, the magnet in the pan and the magnetic drain plug are always clean.
Thinking it was the torque converter, which I did have some vibration issues with, I went ahead and replaced it. It's a lot smoother now and zero vibration issues, but it didn't resolve the whining problem. I also checked all exhaust shields, etc. whilst I was in there, just in case anything was loose and would happen to rattle - everything there is tight. Any input from GM transmissions gurus would be much appreciated - thank you!
The unit has 115,000 miles on it. It's had very regular fluid (Dexron-VI with LubeGard) and filter (ACDelco TF-289) changes - a drain and refill every 6,250 miles and a filter replacement/pan drop every 25,000 miles. I have a Derale cooling pan, which an extra 2 quart capacity and drain plug. The reason I use a TF-289 shallow pan filter and not the 24208576 deep pan filter is because this particular pan has big cooling tubes, and you can't bolt the pan back on with the deep pan filter. The fluid is always a nice cherry red, the magnet in the pan and the magnetic drain plug are always clean.
Thinking it was the torque converter, which I did have some vibration issues with, I went ahead and replaced it. It's a lot smoother now and zero vibration issues, but it didn't resolve the whining problem. I also checked all exhaust shields, etc. whilst I was in there, just in case anything was loose and would happen to rattle - everything there is tight. Any input from GM transmissions gurus would be much appreciated - thank you!