My '98 Malibu has been reluctant to upshift when cold. When the
outside temperature is in the 20s, I let the car warm up for a couple
of minutes, but for the first half mile or so it tends to race instead
of upshifting. Backing off on the accelerator seems to help.
After the first half mile, it shifts normally. I don't recall this
happening in past years. Any suggestions?