I have a 87camaro with a v6 2.8 in it. i have noticed that it will not shift to fourth unless its cool outside but after about 10 minutes of driving it will down shift back to 3rd. i can not figure out why if you have any ideas please help

 

sound like it may be low line pressure. may be because of old fluid? my first step would be trans flush and filter.

 

i got it flushed 5,000 miles ago. the last time i checked it was low so i filled it up to the line after that it would shift to fourth but only for a little while. as you stated above "it may be low line pressure" could it be burning trans fluid?

 

unlikely to be burning fluid. have you checked your coolant, trans fluid may sometimes leak between the integrated trans cooler and the radiator. im guessing you have no visible drips or puddles in the driveway.

 

thank you for your help we pulled the transmission out and the pump was going bad. now it runs like a champ