2003 Taurus Tranny Acting Odd

2003 Taurus, 205,000 miles, I replace a gallon of tranny fluid every year per tranny shop recomendations. It does not always shift correctly. Sometimes when driving really slow and steady it just wants to hold first gear and not shift into second. It does not always want to shift into overdrive it always does eventually. It does not seem to be slipping and I donot believe the motor is reving. I had a mechanic drive it for a couple of days and he said everything seemed ok to him. Sometimes it will act up and sometimes it won't. Does not seem to matter if it is cold or hot outside and it does not seem to matter if the car is a operating temperature or not. Tach also seems to be a little squirrly every now and then. Anybody have any ideas or is my car just acting its age?

I'm no transmission guy, but I'd start by monitoring the Transmission Fluid Temperature (TFT) sensor to see if it seems to be functioning properly, along with monitoring the shaft speed sensors. The problem with the above is the standard scan tools will not be able to monitor these parameters, it would require a professional scan tool.

-Rod

Explain about the "tranny shop" recomending you replace a gallon of fluid every year.
I have an '02 that I drain, change the filter, thoroughly clean the pan, and replace near 7 qts of Mercon V every 30,000 miles, I've never heard of what you say.

They said that by replacing 4 or 5 quarts of fluid would revitalize the rest of the fluid. I have no reason to not believe them. I have not had a chance to check into the TFT like mentioned above or anything else yet. Pushing 210,000 and it is still acking up but it is still getting me back and forth. I applaud you for taking care of yours the way you do. I feel I take pretty good care of my stuff, I always get a lot of mileage out of my vehicles, my american made vehicles, so I have to be doing something right, of course my practice on the transmission may be questionable.

Anyone ever drop the transmission pan, clean it out, put in a new filter and top it off with Mercon V? Most "tranny" places use the cheapest fluid they can get away with and don't care about the manufacturer recomendations. Sounds like you may have been listening to a guy from one of those shops.

I agree with you on the shops using the cheapest stuff to get the job done. I try to always watch what they are doing, I was there when the filter and fluid was changed, everything looked on the up and up. I would drop the pan and do it myself if I thought it would fix my problem., I talked to Ford about it and they were leaning towards a sensor like the guy above mentioned but to find out for sure which sensor it is, I would have to belly up and let one of their techs diagnose the problem. I don't want to go that route yet.