RPM stuff

[Mark_be]

Hello,

I just drove home from work and noticed 2 strange things:

* I was driving 58mph, which is about 1950 rpm and after a while it changed to 2000 rpm while the speed stayed the same.
* I slowed down on the exit lane and could hear the engine slow down, but the gauge stayed at 2000 and suddenly dropped to 1500 or so.

What could cause this? Some kind of sensor?

Another question while we're at it: at which rpm should the 4R100 switch gears when pushing the pedal halfway? Mine stays in the same gear until 2500-2800 rpm depending on the gear. Is that normal? Isn't that a high rpm? It does get its maximum torque at 1500, so why shifting so late then??


Thanks for all info (again!),
Mark

[AOx4]

What truck do you have? Year, engine etc. You said E40D but the 7.3 doesnt have an E40D, it has the 4R100 (automatic).

[Mark_be]

Sorry, you're right, It's the 4R100. I have a 2001 7.3 PSD.

[Mark_be]

(corrected my error about transmission type in original post)

[Mark_be]

Update: Seems like the gage itself is sticking, because when I give it a knock on the front, the arrow goes back to the normal position. The only thing that keeps bothering me is why it first goes to 2000 rpm to get stuck.