99 Silverado help

Hey everyone,
I have a 99 Silverado Z71 that has been acting interesting lately. It has
120,000 miles on it so i'm kinda beginning to worry a bit. At times, when
driving it will idle about 750-1000 RPMs and you can feel it pulling when you
come to a stop. anyway, when you accelerate, it feels like the transmission is
holding the gears long and the shifts are harder. The 'tow' option is not
engaged and in just regular overdrive. I find that it does this on occasion
and i've had the transmission serviced/flushed at 38,000 miles and 75,000 miles
by the Chevy dealer. I also sometimes find that it does this right after
taking it to the dealer and getting the fluids changed. most of the time when
i cut it off and come back and start it back up things are fine. Are there any
thoughts or suggestions of what it might be and is this a precursor to things
going wrong?
Thanks in advance!

"OldBluein2" <oldbluein2.DeleteThis@aol.com> wrote in message
news:20050103205856.21518.00002426@mb-m11.aol.com...
 > Hey everyone,
 > I have a 99 Silverado Z71 that has been acting interesting lately. It has
 > 120,000 miles on it so i'm kinda beginning to worry a bit. At times, when
 > driving it will idle about 750-1000 RPMs and you can feel it pulling when
 > you
 > come to a stop. anyway, when you accelerate, it feels like the
 > transmission is
 > holding the gears long and the shifts are harder. The 'tow' option is not
 > engaged and in just regular overdrive. I find that it does this on
 > occasion
 > and i've had the transmission serviced/flushed at 38,000 miles and 75,000
 > miles
 > by the Chevy dealer. I also sometimes find that it does this right after
 > taking it to the dealer and getting the fluids changed. most of the time
 > when
 > i cut it off and come back and start it back up things are fine. Are
 > there any
 > thoughts or suggestions of what it might be and is this a precursor to
 > things
 > going wrong?
 > Thanks in advance!

First thing is first, head to your nearest Autozone and have the PCM scanned
for trouble codes.

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