Temporary stuck in high revs going down mountain highway

Trying to figure this out since it happened before in the same exact spot going down a mountain highway.

engine revs to about 4000rpm and kind of gets stuck there as I am going down a fairly steep grade at moderate altitude in the northeast. Slight breaking seems to make it worst as the transmission was having trouble shifting back down. Bed was full of hiking and camping gear so I suppose I was carrying some good weight as well. Anyone else experience this?

 

I noticed higher revs coming down about a 8 percent grade when I had my trailer attached and in Tow mode. I thought the truck was programmed to use the engine for braking and it hasn't done it anywhere else other than one time.

It seemed to be useful to avoid burning up the brakes if it was intended as such. Not too sure now, perhaps the user manual can shed some light on this?

 

Are you running cruise control?

 

Cruise control will downshift to engine brake. Don't think it does it if you're simply coasting, but definitely does it on cruise

 

No cruise in my case. I never use it.

 

Not trying to be a jerk, but are you complaining about the engine braking going down a hill? Or just curious why it does it? Unless I'm misunderstanding what you are asking, the truck is shifting down a few gears to use the engine braking to slow down the vehicle instead of relying solely on the brakes. It's a great way to scrub speed and slow down or decrease acceleration from the hills without putting heat in to the brakes.

If I give the brakes a good stab going down a decent hill, my truck will downshift and start engine braking automatically without engaging tow/haul or cruise. If tow/haul is engages it does it a little sooner with a little less aggressive brake application. That's on a Gen2 but I don't see any reason they would remove that feature/programming for the Gen3 platform. It is a very handy and worthwhile feature, IMO. I often shift in to S mode on hills and drop a gear or two at the top of the a hill or pass if I need limit or maintain speed.

 

I haven’t really experienced this feature on this or my previous trucks. The high rev and noise was a bit alarming given the current state of this V6 but it makes sense now. I was not in tow mode but as I said the bed was full of a lot of weight from our July 4 trip.

So if the engine brake initiates should I also brake going down hill or otherwise should I just let off the pedal and let it do its thing until it naturally shifts again?

 

I know the AB60E tranny in the Gen2/2.5 5.7L has some AI programming in the electronics that also does a little down-shifting as one slows, in anticipation of braking, and as has been said, it will down-shift if the truck speeds up on a down hill run when using cruise control. I'm guessing your Gen 3's electronically controlled tranny also has AI features in the programming, with or without cruise in use.

 

Gotcha. Ya, it’s normal for it to downshift to minimize braking effort for the driver. It also helps keeps pads and rotors cooler decreasing brake fade in order to be be able to stop safely. It also lessens the chance of warped rotors.

You should still use your brakes as you see fit to maintain speed or slow down; the engine braking is just helping you with that. In the Gen2, it will usually hold the gear until you apply the gas pedal or the vehicle senses you are on flat ground (via the accelerometers it uses as sensors) and have are slowed down below a certain speed.

 

thank you

 

I find the engine braking to be useful on mountain highways when towing my 5400+ lb travel trailer…. However, I took a detour on the Blueridge Pkwy last week and at 25-30mph on steep decents it was not enough and I had to get on my brakes more. It cooked my tundra brakes so I stopped to let them cool. Only the passenger side got hot… driver side brakes were only warm to touch.
As an aside, on hwy mountain passes I believe that using radar cruise is unwise as it applies the brakes before engine braking, causing the brakes to wear. Using non-radar cruise forced the engine and transmission to work in harmony to control speed. My 2 cents.

 

To the OP, for what it’s worth, my previous F150 would take forever to upshift after a decent / slope and on flats sounded like it was going to throw a rod.

 

When I learned to drive on stick shift, I was taught to drop down in gears when doing doing a hill until you reached the gear where the vehicle maintained your desired descending speed without the use of brakes. Sounds like the truck is trying to do this on its own.

when driving my truck home after purchasing it, I passed through TN which has a several mile long 8 grade descent. I can’t remember if I was on cruise control but the truck did not downshift and I had to occasional step on the brakes to stop from accelerating.

it’s also the only time my hybrid battery made it to full

 

@demfer hit the gas a little and it will usually upshift. That has been my experience, but I only notice this while in Tow mode with a trailer.