high rpms at 65-70mph

[gpgtman83]

i have a 2000 pontiac grand prix gt and at 65-70 mph on the hiway the tach reads anywhere from 2500 to 2700 rpms.when i got the car it had 98,000 miles on it and at the same speeds it read 2000 rpms.now the car has 123000 miles on it and it is doing this any help with this would be nice

 

[minichopper6hp]

You have lost 4th gear. It happens to the best of us.

 

[gpgtman83]

it shifts into overdrive and stays in overdrive but almost like it is slipping.i have did all the regular maintenance oil change filters etc. but never had the trans serviced.

 

[minichopper6hp]

Are you sure because it is hard to believe that you are losing 700 rpm to a failed tcc.

 

[gpgtman83]

yeah im sure other people have told me to change the filter and have it flushed but im kind of leary to have that done cause i had a friend that had a buick and had the flush done.before he had it done the trans worked fine after it was done the trans quit after 7600 miles

 

[Jakegday]

dont flush, just drain and refill. also replace filter. thats what ive read is best to do

 

[gpgtman83]

thanks ill try that if that dont work ill take the trans out of my 97.or it just might be a reason to trade for a gxp i want.

 

[Bio248]

70-75 mph on a trans with 3.29s (GT) is going to put you in the higher 2000s for RPM.

 

[matt5112]

69 mph should be 2 grand with stock tires/wheels and 3.29's in fourth.

In third, 72 mph = 3 grand.

 

[Nickell]

let completely off the gas and take off the cruise and wait until it shifts then ease up to speed.