2017 Expedition, 3.5L V6, six speed auto. When I come down a steep mountain road and put the transmission in manual I get a surging of the engine. I am typically doing about 40 mph and in 2nd or 3rd gear and I find that the engine surges about once per second. I called the dealer and talked to them about it but they didn't think it was anything out of the ordinary. My previous vehicle was a 2010 Suburban, also with a six speed automatic, and it didn't do this at all. When I shifted into a lower gear it just increased the rpm's and maintained a smooth descent. Anybody else have this experience? Is it anything to be concerned about?

 

During a surge event, if you just barely add in some throttle does the idle smooth?

 

Not sure what happens when I do that. I will be able to test it again on Monday and will let you know. I suspect that it will smooth it out and that it will be hard to add just enough throttle but I will give it a try.

 

So yesterday I did the same descent, Alta Ski Resort to Salt Lake Valley floor and the problem didn't recur. It was as smooth as could be under the exact same circumstances. Same speed and same gears. It is possible that there was an issue with break in? I had about 800 miles on the vehicle the first time it occurred and I now have a little over 2000.

 

I originally posted this last year and didn't see much interest. I do appreciate the one reply that I got. This year I am back in ski season mode and the vehicle is still surging like mad. I had a friend with me who owns a Tahoe and he was not impressed with what the Ford was doing. As I said before, I talked to the dealer and he wasn't helpful and said that it isn't a problem. I think it is. Has anyone else had the same problem?