2000 s-10 transmission question

hi, i have a 2000 s-10 2.2 liter aotumatic. i noticed when the truck is cold and i drive down the road at 55 to 60 mph my rpm's are around 2000 but when it is good and warmed up it jumps to 2600 rpm's. it seems like the longer i run it the more it does not want to shift into overdrive.i have had a problem where i was going down the road and all of a sudden the rpm's jumped to 3500. it did noy feel like it slipped or anything just like it would not shift up. i stopped shut the truck off waited 5 minutes.started truck up and drove down the road it ran perfect for about another hour then done the same thing.any tips on what it might be would be greatly appreciated.

hi, i have a 2000 s-10 2.2 liter aotumatic. i noticed when the truck is cold and i drive down the road at 55 to 60 mph my rpm's are around 2000 but when it is good and warmed up it jumps to 2600 rpm's. it seems like the longer i run it the more it does not want to shift into overdrive.i have had a problem where i was going down the road and all of a sudden the rpm's jumped to 3500. it did noy feel like it slipped or anything just like it would not shift up. i stopped shut the truck off waited 5 minutes.started truck up and drove down the road it ran perfect for about another hour then done the same thing.any tips on what it might be would be greatly appreciated.

What is the mileage and service history on transmissioon?
Any cfheck engine lights?
Engine running goode?
Fluid level and fluid condition?
You need to get it on a engine/transmission capable scanner and check for codes engine and transmission and read out all transmission ahift and slipage data.

Post back any codes.

the engine runs good now. i had the head redone back in july. and just put on a timing chain. it has about 170000 miles on it.about 2 years ago i had the transmission flushed.a parts dealer put the computer on it and said it was a transmission code.but i havent went any farther than that.i was just wandering if there are some kind of sensors that could be causing it.like i mentioned earlier there feels to be no slippage

Go to Advance / Zone, and get a scan like MT was sayin'. They'll tell you the code. You likely have codes (P1870) stored as 'H' History codes, even if the check engine light is out.

We need that to go further...

the engine runs good now. i had the head redone back in july. and just put on a timing chain. it has about 170000 miles on it.about 2 years ago i had the transmission flushed.a parts dealer put the computer on it and said it was a transmission code.but i havent went any farther than that.i was just wandering if there are some kind of sensors that could be causing it.like i mentioned earlier there feels to be no slippage

That is all a good reason to get a transmission/engine capable sanner on it.
What was the code no?

Post back codes and transmission data for more help.

Go to Advance / Zone, and get a scan like MT was sayin'. They'll tell you the code. You likely have codes (P1870) stored as 'H' History codes, even if the check engine light is out.

We need that to go further...

I said to get it on a good transmission/engine capable scanner.

Auto zone and advance parts places can not do that.
They only scan OBD11 codes.
Not much help on transmission problems.