05 sunfire, strange shifting

[bandb]

05 sunfire. automatic. 55,000 miles. no codes present with cheap actron scanner.

i have had this car for about 15,000 miles and it always seem to shift into 3rd gear too soon.

lately it seems like it is slipping a little when it goes into 3rd but thats not even the biggest problem, when it shifts into 3rd it will immediately shift into 4th (overdrive?). this can all happen around 30mph.

trans fluid looks fine and is full. seems to shift fine if you shift it manually.

any thoughts are helpful.

 

[melsg5]

you need to have the transmission checked by a shop that can hook up diagnostic equipment to the transmission. You may have an issue with the shift solenoids. The car is low mileage but is 9 years old, has the transmission filter and fluid ever been changed?

 

[bandb]

i have never changed it and would assume no one else has due to the millage.

i have read that these cars have an issue with the 2-3rd shift solenoid however it seems to usually be accompanied by a check engine light.

i wish these cars had the valve body under the pan because it would be a no brainer to change the fluid/filter/solenoid just to be safe.

do you think a dealer would be better suited for a diagnosis of this problem, or a tranny shop?

 

[melsg5]

if the private shop has ASE certified technicians in transmissions they may be the less expensive route to select.