plumbcrazy

I want to thank you for your input. Turns out it is torque converter lockup and is normal. Thank you again.

I really appreciate your input. My F150 has a 3.7 flex fuel V6. I understand what you’re saying about the difference in age and vehicle but my concern is that I have never driven a vehicle that does this type of activity while still in a particular gear. I believe that the tech has driven around in the vehicle with his diagnostic equipment and the conclusion it that it is that it is normal operation. I have two questions regarding this. Is it possible the diagnostics aren’t showing up as a fault because the problem is mechanical and not electrical? Also, when the torque converter locks up, and I understand what you mean when you say this, is it truly normal for the RPMs to drop so significantly when this happens? If I drive an identical vehicle on their lot am I going to experience the same thing? It sounds like you are telling me that I will. I appreciate your interest and I thank you in advance for your response.

Just purchased a 2016 Expedition XLT w/25000 miles. This is a beautiful truck. One owner , never a rental, not a scratch. I purchased it from a dealer 700 miles from my home. Long irrelevant story here....Anyway, the vehicle is still under original factory warranty. My problem is the transmission- 3rd gear specifically. Upon cold startup, the trans shifts as it should , into 3rd gear and pulls into 4th. Behaves exactly as it should and will go through the gears properly 2-3 times until it warms up even just a little bit. THEN, it will shift normally into third but almost immediately the rpms will drop and it "feels" like it went into 4th but it didn't. It seems to find a 3rd gear "high" This will occur under light and full load-- it doesn't matter. i've taken it to a local dealer and they say it's performing properly. I call BS. They say it doesn't produce a code but I don't accept that as an actual answer. Computers are not infallible. The whole driving experience is garbage in my mind. Still, I want to be reasonable. ( the dealer still has the vehicle and I haven't picked it up yet). There is no way this can be considered "normal" regardless of what the computer says. It feels like a torque converter that's lost pressure and slipping but it's only in 3rd gear. Extremely consistent behavior. NEVER happening in another gear. My 2011 F-150 with 6 speed auto and 175,000 trouble free miles shifts BETTER! I am hoping an experienced tech will see this and offer some guidance. I feel like my next move is to try to get a Ford Engineer on site to check this out. I'm discouraged and looking for help. THANKS!