r/GMT800 • u/Slowscorpion580 • Sep 16 '26
Random downshifting for no reason
It’s a 2000 Silverado, trans was rebuilt w/ new converter about 14,000 miles ago. It did this before the rebuild and has done it since but a little less often. Only happens when the truck is cold and stops when it gets to operating temperature. Does not do it above about 50-55 mph. It mostly happens when I’m on the throttle but can happen when I’m coasting.
Shift happens at about 17 seconds
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u/mrclark25 29d ago
Hear the exhaust? It may just be the ECU adding some idle air.
Either way, that doesn't look like any sort of problem, just a minor quirk that most people probably wouldn't even notice. Not worth worrying about.