So, I recently purchased a 2008 Expedition and after joining this forum, my eye cought this post. It appears we are having the same issues.
The seller of my Expedition had a back story for it. He said the engine was replaced and after 50k miles the vehicle was parked outside for about 6 months after it was used to move the family cross country.
Being more diligent with the history, I discovered the wife and kids loaded the vehicle and towed a moving trailer across the the county and when they got to Texas she replaced the engine. She then had the vehicle parked for 6 months until it was traded in.
My theory, wife loaded up the kids and trailer and never looked back and probably didn't turn off the overdrive. The vehicle overheated, leading her to replace the engine. After the swap, she started having transmission issues and figured it was time to trade before she had to buy another high dollar part.
So, now the vehicle is mine. When I did my inspection. Checked all the fluids. Everything looked great until I checked the transmission fluid. When I opened the dipstick port the fluid was somewhat foamy which made it hard to read the dipstick and the sample I pulled was no longer red but a dark red/brown.... (funny thing, whoever last checked the transmission fluid, broke the the dipstick and super glued it back together).
I drove the Expedition (we named her Big Bertha) for 2 hours to identify any other issues I missed during my visual inspection. Bertha was doing great. A side from the excessive amounts of Cheetos matted in the rear seat mounts and tierod ends that needed to be replaced, she was great....well almost great.
Around town, Bertha did great. But when I got her to cruising speed on the highway, there was a shudder while under load going uphill (and it sounded almost like misfires). I could feel the transmission trying to shift and could see the rpm dance up. The check engine light started to blink. So I let off the accelerator and started to slow. Finally, the transmission shifted to another gear. The check engine light stopped blinking. I got it back up to speed and again, going uphill the same thing happened. This time I turned off the Overdrive. Once I did that, the transmission shifted gears and the check engine light stopped blinking.
Additionally, when I drove back home after I stopped at the stoplight. I could feel the car lurching forward while at a few stop with the brake applied.
While at home I Drained about a gallon of transmission fluid and replaced it. Drove it for about a week and still have the same issue.
I am a jack of all trades but a master of none. I'm not ashamed to say the only thing I know about transmissions is how to check the fluids and when to turn off the overdrive. So, if anyone and help with this Pandora's box it would be greatly appreciated.
