I should state first off that I'm not much of a car guy when it comes to the actual mechanics behind them. I just wanted to check if there's anything going wrong with my transmission.
I drive a 03 GMC Envoy(Equivalent of a trailblazer) with a Vortec 4200 4.2l Inline 6. I just had my transmission fluid(100% flush) and filter changed.
When I press the pedal down about 75%, the tachometer rises quite a bit and suddenly I get a ton of acceleration out of nowhere and the RPMs jump really high,almost like a turbo kicking in. (Shifts at 6k, redline is 6300rpm) It does not feel like it's shifting. I should also mention that my engine is naturally aspirated, and there's no modifications.
I'll be at 3100RPM then it'll suddenly jump to 5500 in rapid acceleration.
I don't know if it's from the electronic fuel injection system or something, but it just seems weird to me. I've never heard of cars doing this.
Is this natural? If not, what are some problems I should look for?