This has been bothering me for a while and I've just actually gotten around to actually looking into this issue a little deeper. My speedometer in my car is less than, I guess you could say, responsive and has been ever since I bought the car. Upon acceleration, the speedometer reads correctly and accurately although it looks like GM designed it to almost be a smooth and gradual readout, instead of a hyper-precise one. That being said, the tachometer is extremely precise and reacts quite quickly. Upon deceleration, however, everything changes. I've noticed, especially when coming to a stop or pulling into a parking spot, that the speedometer will read well over 5 mph when stopping abruptly and then slowly sink down to zero. Interestingly enough, it acts almost as if it's waiting for me to stop pressing the brake pedal. This is most evident when pulling into my parking spot at my house, where I commonly do about 10mph down my driveway, bang a left into my spot and stop. I watch as the needle goes from reading 10mph to around 5, and then slowly falls to 1, taking about a second to do so, then I take my foot off the brake and rip the e-brake handle, and my speedo needle finally falls to 0.

Has anyone else experienced this? Please note that I have owned and used two gauge clusters in this vehicle, both acted the same way. I'm not sure if this is how the vehicle was designed, or if something is at fault here, but I'd sure like to find out.

Thanks in advance,
Alcolawl

My GT did something like that months ago. not long after check engine light came on and the speedo stopped working all together. Speed sensor was clogged with metal shavings. pop out your speed sensor and see what it looks like

"Is that your exhaust or is that the sound of someone deflating a cat?"